# lodash v3.10.1 ## `Array` * `_.chunk` * `_.compact` * `_.difference` * `_.drop` * `_.dropRight` * `_.dropRightWhile` * `_.dropWhile` * `_.fill` * `_.findIndex` * `_.findLastIndex` * `_.first` * `_.flatten` * `_.flattenDeep` * `_.head` -> `first` * `_.indexOf` * `_.initial` * `_.intersection` * `_.last` * `_.lastIndexOf` * `_.object` -> `zipObject` * `_.pull` * `_.pullAt` * `_.remove` * `_.rest` * `_.slice` * `_.sortedIndex` * `_.sortedLastIndex` * `_.tail` -> `rest` * `_.take` * `_.takeRight` * `_.takeRightWhile` * `_.takeWhile` * `_.union` * `_.uniq` * `_.unique` -> `uniq` * `_.unzip` * `_.unzipWith` * `_.without` * `_.xor` * `_.zip` * `_.zipObject` * `_.zipWith` ## `Chain` * `_` * `_.chain` * `_.tap` * `_.thru` * `_.prototype.chain` * `_.prototype.commit` * `_.prototype.concat` * `_.prototype.plant` * `_.prototype.reverse` * `_.prototype.run` -> `value` * `_.prototype.toJSON` -> `value` * `_.prototype.toString` * `_.prototype.value` * `_.prototype.valueOf` -> `value` ## `Collection` * `_.all` -> `every` * `_.any` -> `some` * `_.at` * `_.collect` -> `map` * `_.contains` -> `includes` * `_.countBy` * `_.detect` -> `find` * `_.each` -> `forEach` * `_.eachRight` -> `forEachRight` * `_.every` * `_.filter` * `_.find` * `_.findLast` * `_.findWhere` * `_.foldl` -> `reduce` * `_.foldr` -> `reduceRight` * `_.forEach` * `_.forEachRight` * `_.groupBy` * `_.include` -> `includes` * `_.includes` * `_.indexBy` * `_.inject` -> `reduce` * `_.invoke` * `_.map` * `_.partition` * `_.pluck` * `_.reduce` * `_.reduceRight` * `_.reject` * `_.sample` * `_.select` -> `filter` * `_.shuffle` * `_.size` * `_.some` * `_.sortBy` * `_.sortByAll` * `_.sortByOrder` * `_.where` ## `Date` * `_.now` ## `Function` * `_.after` * `_.ary` * `_.backflow` -> `flowRight` * `_.before` * `_.bind` * `_.bindAll` * `_.bindKey` * `_.compose` -> `flowRight` * `_.curry` * `_.curryRight` * `_.debounce` * `_.defer` * `_.delay` * `_.flow` * `_.flowRight` * `_.memoize` * `_.modArgs` * `_.negate` * `_.once` * `_.partial` * `_.partialRight` * `_.rearg` * `_.restParam` * `_.spread` * `_.throttle` * `_.wrap` ## `Lang` * `_.clone` * `_.cloneDeep` * `_.eq` -> `isEqual` * `_.gt` * `_.gte` * `_.isArguments` * `_.isArray` * `_.isBoolean` * `_.isDate` * `_.isElement` * `_.isEmpty` * `_.isEqual` * `_.isError` * `_.isFinite` * `_.isFunction` * `_.isMatch` * `_.isNaN` * `_.isNative` * `_.isNull` * `_.isNumber` * `_.isObject` * `_.isPlainObject` * `_.isRegExp` * `_.isString` * `_.isTypedArray` * `_.isUndefined` * `_.lt` * `_.lte` * `_.toArray` * `_.toPlainObject` ## `Math` * `_.add` * `_.ceil` * `_.floor` * `_.max` * `_.min` * `_.round` * `_.sum` ## `Number` * `_.inRange` * `_.random` ## `Object` * `_.assign` * `_.create` * `_.defaults` * `_.defaultsDeep` * `_.extend` -> `assign` * `_.findKey` * `_.findLastKey` * `_.forIn` * `_.forInRight` * `_.forOwn` * `_.forOwnRight` * `_.functions` * `_.get` * `_.has` * `_.invert` * `_.keys` * `_.keysIn` * `_.mapKeys` * `_.mapValues` * `_.merge` * `_.methods` -> `functions` * `_.omit` * `_.pairs` * `_.pick` * `_.result` * `_.set` * `_.transform` * `_.values` * `_.valuesIn` ## `String` * `_.camelCase` * `_.capitalize` * `_.deburr` * `_.endsWith` * `_.escape` * `_.escapeRegExp` * `_.kebabCase` * `_.pad` * `_.padLeft` * `_.padRight` * `_.parseInt` * `_.repeat` * `_.snakeCase` * `_.startCase` * `_.startsWith` * `_.template` * `_.trim` * `_.trimLeft` * `_.trimRight` * `_.trunc` * `_.unescape` * `_.words` ## `Utility` * `_.attempt` * `_.callback` * `_.constant` * `_.identity` * `_.iteratee` -> `callback` * `_.matches` * `_.matchesProperty` * `_.method` * `_.methodOf` * `_.mixin` * `_.noConflict` * `_.noop` * `_.property` * `_.propertyOf` * `_.range` * `_.runInContext` * `_.times` * `_.uniqueId` ## `Methods` * `_.templateSettings.imports._` ## `Properties` * `_.VERSION` * `_.support` * `_.support.enumErrorProps` * `_.support.enumPrototypes` * `_.support.nonEnumShadows` * `_.support.ownLast` * `_.support.spliceObjects` * `_.support.unindexedChars` * `_.templateSettings` * `_.templateSettings.escape` * `_.templateSettings.evaluate` * `_.templateSettings.imports` * `_.templateSettings.interpolate` * `_.templateSettings.variable` ## `“Array” Methods` ### `_.chunk(array, [size=1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4624 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.chunk "See the npm package") Creates an array of elements split into groups the length of `size`. If `collection` can't be split evenly, the final chunk will be the remaining elements. #### Arguments 1. `array` *(Array)*: The array to process. 2. `[size=1]` *(number)*: The length of each chunk. #### Returns *(Array)*: Returns the new array containing chunks. #### Example ```js _.chunk(['a', 'b', 'c', 'd'], 2); // => [['a', 'b'], ['c', 'd']] _.chunk(['a', 'b', 'c', 'd'], 3); // => [['a', 'b', 'c'], ['d']] ``` * * * ### `_.compact(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4655 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.compact "See the npm package") Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey. #### Arguments 1. `array` *(Array)*: The array to compact. #### Returns *(Array)*: Returns the new array of filtered values. #### Example ```js _.compact([0, 1, false, 2, '', 3]); // => [1, 2, 3] ``` * * * ### `_.difference(array, [values])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4686 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.difference "See the npm package") Creates an array of unique `array` values not included in the other provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. #### Arguments 1. `array` *(Array)*: The array to inspect. 2. `[values]` *(...Array)*: The arrays of values to exclude. #### Returns *(Array)*: Returns the new array of filtered values. #### Example ```js _.difference([1, 2, 3], [4, 2]); // => [1, 3] ``` * * * ### `_.drop(array, [n=1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4716 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.drop "See the npm package") Creates a slice of `array` with `n` elements dropped from the beginning. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[n=1]` *(number)*: The number of elements to drop. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.drop([1, 2, 3]); // => [2, 3] _.drop([1, 2, 3], 2); // => [3] _.drop([1, 2, 3], 5); // => [] _.drop([1, 2, 3], 0); // => [1, 2, 3] ``` * * * ### `_.dropRight(array, [n=1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4751 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.dropright "See the npm package") Creates a slice of `array` with `n` elements dropped from the end. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[n=1]` *(number)*: The number of elements to drop. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.dropRight([1, 2, 3]); // => [1, 2] _.dropRight([1, 2, 3], 2); // => [1] _.dropRight([1, 2, 3], 5); // => [] _.dropRight([1, 2, 3], 0); // => [1, 2, 3] ``` * * * ### `_.dropRightWhile(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4812 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.droprightwhile "See the npm package") Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that match the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.dropRightWhile([1, 2, 3], function(n) { return n > 1; }); // => [1] var users = [ { 'user': 'barney', 'active': true }, { 'user': 'fred', 'active': false }, { 'user': 'pebbles', 'active': false } ]; // using the `_.matches` callback shorthand _.pluck(_.dropRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user'); // => ['barney', 'fred'] // using the `_.matchesProperty` callback shorthand _.pluck(_.dropRightWhile(users, 'active', false), 'user'); // => ['barney'] // using the `_.property` callback shorthand _.pluck(_.dropRightWhile(users, 'active'), 'user'); // => ['barney', 'fred', 'pebbles'] ``` * * * ### `_.dropWhile(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4867 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.dropwhile "See the npm package") Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.dropWhile([1, 2, 3], function(n) { return n < 3; }); // => [3] var users = [ { 'user': 'barney', 'active': false }, { 'user': 'fred', 'active': false }, { 'user': 'pebbles', 'active': true } ]; // using the `_.matches` callback shorthand _.pluck(_.dropWhile(users, { 'user': 'barney', 'active': false }), 'user'); // => ['fred', 'pebbles'] // using the `_.matchesProperty` callback shorthand _.pluck(_.dropWhile(users, 'active', false), 'user'); // => ['pebbles'] // using the `_.property` callback shorthand _.pluck(_.dropWhile(users, 'active'), 'user'); // => ['barney', 'fred', 'pebbles'] ``` * * * ### `_.fill(array, value, [start=0], [end=array.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4901 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.fill "See the npm package") Fills elements of `array` with `value` from `start` up to, but not including, `end`.

**Note:** This method mutates `array`. #### Arguments 1. `array` *(Array)*: The array to fill. 2. `value` *(*)*: The value to fill `array` with. 3. `[start=0]` *(number)*: The start position. 4. `[end=array.length]` *(number)*: The end position. #### Returns *(Array)*: Returns `array`. #### Example ```js var array = [1, 2, 3]; _.fill(array, 'a'); console.log(array); // => ['a', 'a', 'a'] _.fill(Array(3), 2); // => [2, 2, 2] _.fill([4, 6, 8], '*', 1, 2); // => [4, '*', 8] ``` * * * ### `_.findIndex(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L4961 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findindex "See the npm package") This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(number)*: Returns the index of the found element, else `-1`. #### Example ```js var users = [ { 'user': 'barney', 'active': false }, { 'user': 'fred', 'active': false }, { 'user': 'pebbles', 'active': true } ]; _.findIndex(users, function(chr) { return chr.user == 'barney'; }); // => 0 // using the `_.matches` callback shorthand _.findIndex(users, { 'user': 'fred', 'active': false }); // => 1 // using the `_.matchesProperty` callback shorthand _.findIndex(users, 'active', false); // => 0 // using the `_.property` callback shorthand _.findIndex(users, 'active'); // => 2 ``` * * * ### `_.findLastIndex(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5011 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findlastindex "See the npm package") This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(number)*: Returns the index of the found element, else `-1`. #### Example ```js var users = [ { 'user': 'barney', 'active': true }, { 'user': 'fred', 'active': false }, { 'user': 'pebbles', 'active': false } ]; _.findLastIndex(users, function(chr) { return chr.user == 'pebbles'; }); // => 2 // using the `_.matches` callback shorthand _.findLastIndex(users, { 'user': 'barney', 'active': true }); // => 0 // using the `_.matchesProperty` callback shorthand _.findLastIndex(users, 'active', false); // => 2 // using the `_.property` callback shorthand _.findLastIndex(users, 'active'); // => 0 ``` * * * ### `_.first(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5030 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.first "See the npm package") Gets the first element of `array`. #### Aliases *_.head* #### Arguments 1. `array` *(Array)*: The array to query. #### Returns *(*)*: Returns the first element of `array`. #### Example ```js _.first([1, 2, 3]); // => 1 _.first([]); // => undefined ``` * * * ### `_.flatten(array, [isDeep])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5054 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.flatten "See the npm package") Flattens a nested array. If `isDeep` is `true` the array is recursively flattened, otherwise it's only flattened a single level. #### Arguments 1. `array` *(Array)*: The array to flatten. 2. `[isDeep]` *(boolean)*: Specify a deep flatten. #### Returns *(Array)*: Returns the new flattened array. #### Example ```js _.flatten([1, [2, 3, [4]]]); // => [1, 2, 3, [4]] // using `isDeep` _.flatten([1, [2, 3, [4]]], true); // => [1, 2, 3, 4] ``` * * * ### `_.flattenDeep(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5075 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.flattendeep "See the npm package") Recursively flattens a nested array. #### Arguments 1. `array` *(Array)*: The array to recursively flatten. #### Returns *(Array)*: Returns the new flattened array. #### Example ```js _.flattenDeep([1, [2, 3, [4]]]); // => [1, 2, 3, 4] ``` * * * ### `_.indexOf(array, value, [fromIndex=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5108 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.indexof "See the npm package") Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`. If `array` is sorted providing `true` for `fromIndex` performs a faster binary search. #### Arguments 1. `array` *(Array)*: The array to search. 2. `value` *(*)*: The value to search for. 3. `[fromIndex=0]` *(boolean|number)*: The index to search from or `true` to perform a binary search on a sorted array. #### Returns *(number)*: Returns the index of the matched value, else `-1`. #### Example ```js _.indexOf([1, 2, 1, 2], 2); // => 1 // using `fromIndex` _.indexOf([1, 2, 1, 2], 2, 2); // => 3 // performing a binary search _.indexOf([1, 1, 2, 2], 2, true); // => 2 ``` * * * ### `_.initial(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5139 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.initial "See the npm package") Gets all but the last element of `array`. #### Arguments 1. `array` *(Array)*: The array to query. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.initial([1, 2, 3]); // => [1, 2] ``` * * * ### `_.intersection([arrays])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5157 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.intersection "See the npm package") Creates an array of unique values that are included in all of the provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. #### Arguments 1. `[arrays]` *(...Array)*: The arrays to inspect. #### Returns *(Array)*: Returns the new array of shared values. #### Example ```js _.intersection([1, 2], [4, 2], [2, 1]); // => [2] ``` * * * ### `_.last(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5207 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.last "See the npm package") Gets the last element of `array`. #### Arguments 1. `array` *(Array)*: The array to query. #### Returns *(*)*: Returns the last element of `array`. #### Example ```js _.last([1, 2, 3]); // => 3 ``` * * * ### `_.lastIndexOf(array, value, [fromIndex=array.length-1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5237 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.lastindexof "See the npm package") This method is like `_.indexOf` except that it iterates over elements of `array` from right to left. #### Arguments 1. `array` *(Array)*: The array to search. 2. `value` *(*)*: The value to search for. 3. `[fromIndex=array.length-1]` *(boolean|number)*: The index to search from or `true` to perform a binary search on a sorted array. #### Returns *(number)*: Returns the index of the matched value, else `-1`. #### Example ```js _.lastIndexOf([1, 2, 1, 2], 2); // => 3 // using `fromIndex` _.lastIndexOf([1, 2, 1, 2], 2, 2); // => 1 // performing a binary search _.lastIndexOf([1, 1, 2, 2], 2, true); // => 3 ``` * * * ### `_.pull(array, [values])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5285 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pull "See the npm package") Removes all provided values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons.

**Note:** Unlike `_.without`, this method mutates `array`. #### Arguments 1. `array` *(Array)*: The array to modify. 2. `[values]` *(...*)*: The values to remove. #### Returns *(Array)*: Returns `array`. #### Example ```js var array = [1, 2, 3, 1, 2, 3]; _.pull(array, 2, 3); console.log(array); // => [1, 1] ``` * * * ### `_.pullAt(array, [indexes])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5332 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pullat "See the npm package") Removes elements from `array` corresponding to the given indexes and returns an array of the removed elements. Indexes may be specified as an array of indexes or as individual arguments.

**Note:** Unlike `_.at`, this method mutates `array`. #### Arguments 1. `array` *(Array)*: The array to modify. 2. `[indexes]` *(...(number|number[])*: The indexes of elements to remove, specified as individual indexes or arrays of indexes. #### Returns *(Array)*: Returns the new array of removed elements. #### Example ```js var array = [5, 10, 15, 20]; var evens = _.pullAt(array, 1, 3); console.log(array); // => [5, 15] console.log(evens); // => [10, 20] ``` * * * ### `_.remove(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5379 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.remove "See the npm package") Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`.

**Note:** Unlike `_.filter`, this method mutates `array`. #### Arguments 1. `array` *(Array)*: The array to modify. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the new array of removed elements. #### Example ```js var array = [1, 2, 3, 4]; var evens = _.remove(array, function(n) { return n % 2 == 0; }); console.log(array); // => [1, 3] console.log(evens); // => [2, 4] ``` * * * ### `_.rest(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5414 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.rest "See the npm package") Gets all but the first element of `array`. #### Aliases *_.tail* #### Arguments 1. `array` *(Array)*: The array to query. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.rest([1, 2, 3]); // => [2, 3] ``` * * * ### `_.slice(array, [start=0], [end=array.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5432 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.slice "See the npm package") Creates a slice of `array` from `start` up to, but not including, `end`.

**Note:** This method is used instead of `Array#slice` to support node lists in IE < 9 and to ensure dense arrays are returned. #### Arguments 1. `array` *(Array)*: The array to slice. 2. `[start=0]` *(number)*: The start position. 3. `[end=array.length]` *(number)*: The end position. #### Returns *(Array)*: Returns the slice of `array`. * * * ### `_.sortedIndex(array, value, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5492 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sortedindex "See the npm package") Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order. If an iteratee function is provided it's invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is bound to `thisArg` and invoked with one argument; (value).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The sorted array to inspect. 2. `value` *(*)*: The value to evaluate. 3. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(number)*: Returns the index at which `value` should be inserted into `array`. #### Example ```js _.sortedIndex([30, 50], 40); // => 1 _.sortedIndex([4, 4, 5, 5], 5); // => 2 var dict = { 'data': { 'thirty': 30, 'forty': 40, 'fifty': 50 } }; // using an iteratee function _.sortedIndex(['thirty', 'fifty'], 'forty', function(word) { return this.data[word]; }, dict); // => 1 // using the `_.property` callback shorthand _.sortedIndex([{ 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x'); // => 1 ``` * * * ### `_.sortedLastIndex(array, value, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5514 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sortedlastindex "See the npm package") This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order. #### Arguments 1. `array` *(Array)*: The sorted array to inspect. 2. `value` *(*)*: The value to evaluate. 3. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(number)*: Returns the index at which `value` should be inserted into `array`. #### Example ```js _.sortedLastIndex([4, 4, 5, 5], 5); // => 4 ``` * * * ### `_.take(array, [n=1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5540 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.take "See the npm package") Creates a slice of `array` with `n` elements taken from the beginning. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[n=1]` *(number)*: The number of elements to take. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.take([1, 2, 3]); // => [1] _.take([1, 2, 3], 2); // => [1, 2] _.take([1, 2, 3], 5); // => [1, 2, 3] _.take([1, 2, 3], 0); // => [] ``` * * * ### `_.takeRight(array, [n=1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5575 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.takeright "See the npm package") Creates a slice of `array` with `n` elements taken from the end. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[n=1]` *(number)*: The number of elements to take. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.takeRight([1, 2, 3]); // => [3] _.takeRight([1, 2, 3], 2); // => [2, 3] _.takeRight([1, 2, 3], 5); // => [1, 2, 3] _.takeRight([1, 2, 3], 0); // => [] ``` * * * ### `_.takeRightWhile(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5636 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.takerightwhile "See the npm package") Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.takeRightWhile([1, 2, 3], function(n) { return n > 1; }); // => [2, 3] var users = [ { 'user': 'barney', 'active': true }, { 'user': 'fred', 'active': false }, { 'user': 'pebbles', 'active': false } ]; // using the `_.matches` callback shorthand _.pluck(_.takeRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user'); // => ['pebbles'] // using the `_.matchesProperty` callback shorthand _.pluck(_.takeRightWhile(users, 'active', false), 'user'); // => ['fred', 'pebbles'] // using the `_.property` callback shorthand _.pluck(_.takeRightWhile(users, 'active'), 'user'); // => [] ``` * * * ### `_.takeWhile(array, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5691 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.takewhile "See the npm package") Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `array` *(Array)*: The array to query. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the slice of `array`. #### Example ```js _.takeWhile([1, 2, 3], function(n) { return n < 3; }); // => [1, 2] var users = [ { 'user': 'barney', 'active': false }, { 'user': 'fred', 'active': false}, { 'user': 'pebbles', 'active': true } ]; // using the `_.matches` callback shorthand _.pluck(_.takeWhile(users, { 'user': 'barney', 'active': false }), 'user'); // => ['barney'] // using the `_.matchesProperty` callback shorthand _.pluck(_.takeWhile(users, 'active', false), 'user'); // => ['barney', 'fred'] // using the `_.property` callback shorthand _.pluck(_.takeWhile(users, 'active'), 'user'); // => [] ``` * * * ### `_.union([arrays])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5712 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.union "See the npm package") Creates an array of unique values, in order, from all of the provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. #### Arguments 1. `[arrays]` *(...Array)*: The arrays to inspect. #### Returns *(Array)*: Returns the new array of combined values. #### Example ```js _.union([1, 2], [4, 2], [2, 1]); // => [1, 2, 4] ``` * * * ### `_.uniq(array, [isSorted], [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5765 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.uniq "See the npm package") Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons, in which only the first occurence of each element is kept. Providing `true` for `isSorted` performs a faster search algorithm for sorted arrays. If an iteratee function is provided it's invoked for each element in the array to generate the criterion by which uniqueness is computed. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, index, array).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Aliases *_.unique* #### Arguments 1. `array` *(Array)*: The array to inspect. 2. `[isSorted]` *(boolean)*: Specify the array is sorted. 3. `[iteratee]` *(Function|Object|string)*: The function invoked per iteration. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array)*: Returns the new duplicate-value-free array. #### Example ```js _.uniq([2, 1, 2]); // => [2, 1] // using `isSorted` _.uniq([1, 1, 2], true); // => [1, 2] // using an iteratee function _.uniq([1, 2.5, 1.5, 2], function(n) { return this.floor(n); }, Math); // => [1, 2.5] // using the `_.property` callback shorthand _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); // => [{ 'x': 1 }, { 'x': 2 }] ``` * * * ### `_.unzip(array)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5802 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.unzip "See the npm package") This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration. #### Arguments 1. `array` *(Array)*: The array of grouped elements to process. #### Returns *(Array)*: Returns the new array of regrouped elements. #### Example ```js var zipped = _.zip(['fred', 'barney'], [30, 40], [true, false]); // => [['fred', 30, true], ['barney', 40, false]] _.unzip(zipped); // => [['fred', 'barney'], [30, 40], [true, false]] ``` * * * ### `_.unzipWith(array, [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5842 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.unzipwith "See the npm package") This method is like `_.unzip` except that it accepts an iteratee to specify how regrouped values should be combined. The `iteratee` is bound to `thisArg` and invoked with four arguments: (accumulator, value, index, group). #### Arguments 1. `array` *(Array)*: The array of grouped elements to process. 2. `[iteratee]` *(Function)*: The function to combine regrouped values. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array)*: Returns the new array of regrouped elements. #### Example ```js var zipped = _.zip([1, 2], [10, 20], [100, 200]); // => [[1, 10, 100], [2, 20, 200]] _.unzipWith(zipped, _.add); // => [3, 30, 300] ``` * * * ### `_.without(array, [values])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5873 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.without "See the npm package") Creates an array excluding all provided values using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. #### Arguments 1. `array` *(Array)*: The array to filter. 2. `[values]` *(...*)*: The values to exclude. #### Returns *(Array)*: Returns the new array of filtered values. #### Example ```js _.without([1, 2, 1, 3], 1, 2); // => [3] ``` * * * ### `_.xor([arrays])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5893 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.xor "See the npm package") Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the provided arrays. #### Arguments 1. `[arrays]` *(...Array)*: The arrays to inspect. #### Returns *(Array)*: Returns the new array of values. #### Example ```js _.xor([1, 2], [4, 2]); // => [1, 4] ``` * * * ### `_.zip([arrays])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5923 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.zip "See the npm package") Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on. #### Arguments 1. `[arrays]` *(...Array)*: The arrays to process. #### Returns *(Array)*: Returns the new array of grouped elements. #### Example ```js _.zip(['fred', 'barney'], [30, 40], [true, false]); // => [['fred', 30, true], ['barney', 40, false]] ``` * * * ### `_.zipObject(props, [values=[]])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5946 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.zipobject "See the npm package") The inverse of `_.pairs`; this method returns an object composed from arrays of property names and values. Provide either a single two dimensional array, e.g. `[[key1, value1], [key2, value2]]` or two arrays, one of property names and one of corresponding values. #### Aliases *_.object* #### Arguments 1. `props` *(Array)*: The property names. 2. `[values=[]]` *(Array)*: The property values. #### Returns *(Object)*: Returns the new object. #### Example ```js _.zipObject([['fred', 30], ['barney', 40]]); // => { 'fred': 30, 'barney': 40 } _.zipObject(['fred', 'barney'], [30, 40]); // => { 'fred': 30, 'barney': 40 } ``` * * * ### `_.zipWith([arrays], [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L5982 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.zipwith "See the npm package") This method is like `_.zip` except that it accepts an iteratee to specify how grouped values should be combined. The `iteratee` is bound to `thisArg` and invoked with four arguments: (accumulator, value, index, group). #### Arguments 1. `[arrays]` *(...Array)*: The arrays to process. 2. `[iteratee]` *(Function)*: The function to combine grouped values. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array)*: Returns the new array of grouped elements. #### Example ```js _.zipWith([1, 2], [10, 20], [100, 200], _.add); // => [111, 222] ``` * * * ## `“Chain” Methods` ### `_(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L944 "View in source") [Ⓣ][1] Creates a `lodash` object which wraps `value` to enable implicit chaining. Methods that operate on and return arrays, collections, and functions can be chained together. Methods that retrieve a single value or may return a primitive value will automatically end the chain returning the unwrapped value. Explicit chaining may be enabled using `_.chain`. The execution of chained methods is lazy, that is, execution is deferred until `_#value` is implicitly or explicitly called.

Lazy evaluation allows several methods to support shortcut fusion. Shortcut fusion is an optimization strategy which merge iteratee calls; this can help to avoid the creation of intermediate data structures and greatly reduce the number of iteratee executions.

Chaining is supported in custom builds as long as the `_#value` method is directly or indirectly included in the build.

In addition to lodash methods, wrappers have `Array` and `String` methods.

The wrapper `Array` methods are:
`concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`, and `unshift`

The wrapper `String` methods are:
`replace` and `split`

The wrapper methods that support shortcut fusion are:
`compact`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`, `first`, `initial`, `last`, `map`, `pluck`, `reject`, `rest`, `reverse`, `slice`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `toArray`, and `where`

The chainable wrapper methods are:
`after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`, `callback`, `chain`, `chunk`, `commit`, `compact`, `concat`, `constant`, `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`, `defer`, `delay`, `difference`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `fill`, `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`, `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`, `invoke`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, `matchesProperty`, `memoize`, `merge`, `method`, `methodOf`, `mixin`, `modArgs`, `negate`, `omit`, `once`, `pairs`, `partial`, `partialRight`, `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`, `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `restParam`, `reverse`, `set`, `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`, `sortByOrder`, `splice`, `spread`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`, `transform`, `union`, `uniq`, `unshift`, `unzip`, `unzipWith`, `values`, `valuesIn`, `where`, `without`, `wrap`, `xor`, `zip`, `zipObject`, `zipWith`

The wrapper methods that are **not** chainable by default are:
`add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clone`, `cloneDeep`, `deburr`, `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`, `floor`, `get`, `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`, `inRange`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isError`, `isFinite` `isFunction`, `isMatch`, `isNative`, `isNaN`, `isNull`, `isNumber`, `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, `isTypedArray`, `join`, `kebabCase`, `last`, `lastIndexOf`, `lt`, `lte`, `max`, `min`, `noConflict`, `noop`, `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, `startCase`, `startsWith`, `sum`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`, `unescape`, `uniqueId`, `value`, and `words`

The wrapper method `sample` will return a wrapped value when `n` is provided, otherwise an unwrapped value is returned. #### Arguments 1. `value` *(*)*: The value to wrap in a `lodash` instance. #### Returns *(Object)*: Returns the new `lodash` wrapper instance. #### Example ```js var wrapped = _([1, 2, 3]); // returns an unwrapped value wrapped.reduce(function(total, n) { return total + n; }); // => 6 // returns a wrapped value var squares = wrapped.map(function(n) { return n * n; }); _.isArray(squares); // => false _.isArray(squares.value()); // => true ``` * * * ### `_.chain(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6025 "View in source") [Ⓣ][1] Creates a `lodash` object that wraps `value` with explicit method chaining enabled. #### Arguments 1. `value` *(*)*: The value to wrap. #### Returns *(Object)*: Returns the new `lodash` wrapper instance. #### Example ```js var users = [ { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }, { 'user': 'pebbles', 'age': 1 } ]; var youngest = _.chain(users) .sortBy('age') .map(function(chr) { return chr.user + ' is ' + chr.age; }) .first() .value(); // => 'pebbles is 1' ``` * * * ### `_.tap(value, interceptor, [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6054 "View in source") [Ⓣ][1] This method invokes `interceptor` and returns `value`. The interceptor is bound to `thisArg` and invoked with one argument; (value). The purpose of this method is to "tap into" a method chain in order to perform operations on intermediate results within the chain. #### Arguments 1. `value` *(*)*: The value to provide to `interceptor`. 2. `interceptor` *(Function)*: The function to invoke. 3. `[thisArg]` *(*)*: The `this` binding of `interceptor`. #### Returns *(*)*: Returns `value`. #### Example ```js _([1, 2, 3]) .tap(function(array) { array.pop(); }) .reverse() .value(); // => [2, 1] ``` * * * ### `_.thru(value, interceptor, [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6080 "View in source") [Ⓣ][1] This method is like `_.tap` except that it returns the result of `interceptor`. #### Arguments 1. `value` *(*)*: The value to provide to `interceptor`. 2. `interceptor` *(Function)*: The function to invoke. 3. `[thisArg]` *(*)*: The `this` binding of `interceptor`. #### Returns *(*)*: Returns the result of `interceptor`. #### Example ```js _(' abc ') .chain() .trim() .thru(function(value) { return [value]; }) .value(); // => ['abc'] ``` * * * ### `_.prototype.chain()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6109 "View in source") [Ⓣ][1] Enables explicit method chaining on the wrapper object. #### Returns *(Object)*: Returns the new `lodash` wrapper instance. #### Example ```js var users = [ { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 } ]; // without explicit chaining _(users).first(); // => { 'user': 'barney', 'age': 36 } // with explicit chaining _(users).chain() .first() .pick('user') .value(); // => { 'user': 'barney' } ``` * * * ### `_.prototype.commit()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6138 "View in source") [Ⓣ][1] Executes the chained sequence and returns the wrapped result. #### Returns *(Object)*: Returns the new `lodash` wrapper instance. #### Example ```js var array = [1, 2]; var wrapped = _(array).push(3); console.log(array); // => [1, 2] wrapped = wrapped.commit(); console.log(array); // => [1, 2, 3] wrapped.last(); // => 3 console.log(array); // => [1, 2, 3] ``` * * * ### `_.prototype.concat([values])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6162 "View in source") [Ⓣ][1] Creates a new array joining a wrapped array with any additional arrays and/or values. #### Arguments 1. `[values]` *(...*)*: The values to concatenate. #### Returns *(Array)*: Returns the new concatenated array. #### Example ```js var array = [1]; var wrapped = _(array).concat(2, [3], [[4]]); console.log(wrapped.value()); // => [1, 2, 3, [4]] console.log(array); // => [1] ``` * * * ### `_.prototype.plant()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6192 "View in source") [Ⓣ][1] Creates a clone of the chained sequence planting `value` as the wrapped value. #### Returns *(Object)*: Returns the new `lodash` wrapper instance. #### Example ```js var array = [1, 2]; var wrapped = _(array).map(function(value) { return Math.pow(value, 2); }); var other = [3, 4]; var otherWrapped = wrapped.plant(other); otherWrapped.value(); // => [9, 16] wrapped.value(); // => [1, 4] ``` * * * ### `_.prototype.reverse()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6230 "View in source") [Ⓣ][1] Reverses the wrapped array so the first element becomes the last, the second element becomes the second to last, and so on.

**Note:** This method mutates the wrapped array. #### Returns *(Object)*: Returns the new reversed `lodash` wrapper instance. #### Example ```js var array = [1, 2, 3]; _(array).reverse().value() // => [3, 2, 1] console.log(array); // => [3, 2, 1] ``` * * * ### `_.prototype.toString()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6260 "View in source") [Ⓣ][1] Produces the result of coercing the unwrapped value to a string. #### Returns *(string)*: Returns the coerced string value. #### Example ```js _([1, 2, 3]).toString(); // => '1,2,3' ``` * * * ### `_.prototype.value()` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6277 "View in source") [Ⓣ][1] Executes the chained sequence to extract the unwrapped value. #### Aliases *_.prototype.run, _.prototype.toJSON, _.prototype.valueOf* #### Returns *(*)*: Returns the resolved unwrapped value. #### Example ```js _([1, 2, 3]).value(); // => [1, 2, 3] ``` * * * ## `“Collection” Methods` ### `_.at(collection, [props])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6303 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.at "See the npm package") Creates an array of elements corresponding to the given keys, or indexes, of `collection`. Keys may be specified as individual arguments or as arrays of keys. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[props]` *(...(number|number[]|string|string[])*: The property names or indexes of elements to pick, specified individually or in arrays. #### Returns *(Array)*: Returns the new array of picked elements. #### Example ```js _.at(['a', 'b', 'c'], [0, 2]); // => ['a', 'c'] _.at(['barney', 'fred', 'pebbles'], 0, 2); // => ['barney', 'pebbles'] ``` * * * ### `_.countBy(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6351 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.countby "See the npm package") Creates an object composed of keys generated from the results of running each element of `collection` through `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns the composed aggregate object. #### Example ```js _.countBy([4.3, 6.1, 6.4], function(n) { return Math.floor(n); }); // => { '4': 1, '6': 2 } _.countBy([4.3, 6.1, 6.4], function(n) { return this.floor(n); }, Math); // => { '4': 1, '6': 2 } _.countBy(['one', 'two', 'three'], 'length'); // => { '3': 2, '5': 1 } ``` * * * ### `_.every(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6403 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.every "See the npm package") Checks if `predicate` returns truthy for **all** elements of `collection`. The predicate is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Aliases *_.all* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(boolean)*: Returns `true` if all elements pass the predicate check, else `false`. #### Example ```js _.every([true, 1, null, 'yes'], Boolean); // => false var users = [ { 'user': 'barney', 'active': false }, { 'user': 'fred', 'active': false } ]; // using the `_.matches` callback shorthand _.every(users, { 'user': 'barney', 'active': false }); // => false // using the `_.matchesProperty` callback shorthand _.every(users, 'active', false); // => true // using the `_.property` callback shorthand _.every(users, 'active'); // => false ``` * * * ### `_.filter(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6463 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.filter "See the npm package") Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is bound to `thisArg` and invoked with three arguments: (value, index|key, collection).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Aliases *_.select* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the new filtered array. #### Example ```js _.filter([4, 5, 6], function(n) { return n % 2 == 0; }); // => [4, 6] var users = [ { 'user': 'barney', 'age': 36, 'active': true }, { 'user': 'fred', 'age': 40, 'active': false } ]; // using the `_.matches` callback shorthand _.pluck(_.filter(users, { 'age': 36, 'active': true }), 'user'); // => ['barney'] // using the `_.matchesProperty` callback shorthand _.pluck(_.filter(users, 'active', false), 'user'); // => ['fred'] // using the `_.property` callback shorthand _.pluck(_.filter(users, 'active'), 'user'); // => ['barney'] ``` * * * ### `_.find(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6519 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.find "See the npm package") Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is bound to `thisArg` and invoked with three arguments: (value, index|key, collection).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Aliases *_.detect* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(*)*: Returns the matched element, else `undefined`. #### Example ```js var users = [ { 'user': 'barney', 'age': 36, 'active': true }, { 'user': 'fred', 'age': 40, 'active': false }, { 'user': 'pebbles', 'age': 1, 'active': true } ]; _.result(_.find(users, function(chr) { return chr.age < 40; }), 'user'); // => 'barney' // using the `_.matches` callback shorthand _.result(_.find(users, { 'age': 1, 'active': true }), 'user'); // => 'pebbles' // using the `_.matchesProperty` callback shorthand _.result(_.find(users, 'active', false), 'user'); // => 'fred' // using the `_.property` callback shorthand _.result(_.find(users, 'active'), 'user'); // => 'barney' ``` * * * ### `_.findLast(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6540 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findlast "See the npm package") This method is like `_.find` except that it iterates over elements of `collection` from right to left. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(*)*: Returns the matched element, else `undefined`. #### Example ```js _.findLast([1, 2, 3, 4], function(n) { return n % 2 == 1; }); // => 3 ``` * * * ### `_.findWhere(collection, source)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6571 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findwhere "See the npm package") Performs a deep comparison between each element in `collection` and the source object, returning the first element that has equivalent property values.

**Note:** This method supports comparing arrays, booleans, `Date` objects, numbers, `Object` objects, regexes, and strings. Objects are compared by their own, not inherited, enumerable properties. For comparing a single own or inherited property value see `_.matchesProperty`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to search. 2. `source` *(Object)*: The object of property values to match. #### Returns *(*)*: Returns the matched element, else `undefined`. #### Example ```js var users = [ { 'user': 'barney', 'age': 36, 'active': true }, { 'user': 'fred', 'age': 40, 'active': false } ]; _.result(_.findWhere(users, { 'age': 36, 'active': true }), 'user'); // => 'barney' _.result(_.findWhere(users, { 'age': 40, 'active': false }), 'user'); // => 'fred' ``` * * * ### `_.forEach(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6605 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.foreach "See the npm package") Iterates over elements of `collection` invoking `iteratee` for each element. The `iteratee` is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`.

**Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn` may be used for object iteration. #### Aliases *_.each* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array|Object|string)*: Returns `collection`. #### Example ```js _([1, 2]).forEach(function(n) { console.log(n); }).value(); // => logs each value from left to right and returns the array _.forEach({ 'a': 1, 'b': 2 }, function(n, key) { console.log(n, key); }); // => logs each value-key pair and returns the object (iteration order is not guaranteed) ``` * * * ### `_.forEachRight(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6626 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.foreachright "See the npm package") This method is like `_.forEach` except that it iterates over elements of `collection` from right to left. #### Aliases *_.eachRight* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array|Object|string)*: Returns `collection`. #### Example ```js _([1, 2]).forEachRight(function(n) { console.log(n); }).value(); // => logs each value from right to left and returns the array ``` * * * ### `_.groupBy(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6670 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.groupby "See the npm package") Creates an object composed of keys generated from the results of running each element of `collection` through `iteratee`. The corresponding value of each key is an array of the elements responsible for generating the key. The `iteratee` is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns the composed aggregate object. #### Example ```js _.groupBy([4.2, 6.1, 6.4], function(n) { return Math.floor(n); }); // => { '4': [4.2], '6': [6.1, 6.4] } _.groupBy([4.2, 6.1, 6.4], function(n) { return this.floor(n); }, Math); // => { '4': [4.2], '6': [6.1, 6.4] } // using the `_.property` callback shorthand _.groupBy(['one', 'two', 'three'], 'length'); // => { '3': ['one', 'two'], '5': ['three'] } ``` * * * ### `_.includes(collection, target, [fromIndex=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6707 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.includes "See the npm package") Checks if `target` is in `collection` using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`. #### Aliases *_.contains, _.include* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to search. 2. `target` *(*)*: The value to search for. 3. `[fromIndex=0]` *(number)*: The index to search from. #### Returns *(boolean)*: Returns `true` if a matching element is found, else `false`. #### Example ```js _.includes([1, 2, 3], 1); // => true _.includes([1, 2, 3], 1, 2); // => false _.includes({ 'user': 'fred', 'age': 40 }, 'fred'); // => true _.includes('pebbles', 'eb'); // => true ``` * * * ### `_.indexBy(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6769 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.indexby "See the npm package") Creates an object composed of keys generated from the results of running each element of `collection` through `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee function is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns the composed aggregate object. #### Example ```js var keyData = [ { 'dir': 'left', 'code': 97 }, { 'dir': 'right', 'code': 100 } ]; _.indexBy(keyData, 'dir'); // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } _.indexBy(keyData, function(object) { return String.fromCharCode(object.code); }); // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } _.indexBy(keyData, function(object) { return this.fromCharCode(object.code); }, String); // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } ``` * * * ### `_.invoke(collection, path, [args])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6795 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.invoke "See the npm package") Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `methodName` is a function it's invoked for, and `this` bound to, each element in `collection`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `path` *(Array|Function|string)*: The path of the method to invoke or the function invoked per iteration. 3. `[args]` *(...*)*: The arguments to invoke the method with. #### Returns *(Array)*: Returns the array of results. #### Example ```js _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); // => [[1, 5, 7], [1, 2, 3]] _.invoke([123, 456], String.prototype.split, ''); // => [['1', '2', '3'], ['4', '5', '6']] ``` * * * ### `_.map(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6864 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.map "See the npm package") Creates an array of values by running each element in `collection` through `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, index|key, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`.

Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`.

The guarded methods are:
`ary`, `callback`, `chunk`, `clone`, `create`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `flatten`, `invert`, `max`, `min`, `parseInt`, `slice`, `sortBy`, `take`, `takeRight`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`, `random`, `range`, `sample`, `some`, `sum`, `uniq`, and `words` #### Aliases *_.collect* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array)*: Returns the new mapped array. #### Example ```js function timesThree(n) { return n * 3; } _.map([1, 2], timesThree); // => [3, 6] _.map({ 'a': 1, 'b': 2 }, timesThree); // => [3, 6] (iteration order is not guaranteed) var users = [ { 'user': 'barney' }, { 'user': 'fred' } ]; // using the `_.property` callback shorthand _.map(users, 'user'); // => ['barney', 'fred'] ``` * * * ### `_.partition(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6929 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.partition "See the npm package") Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, while the second of which contains elements `predicate` returns falsey for. The predicate is bound to `thisArg` and invoked with three arguments: (value, index|key, collection).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the array of grouped elements. #### Example ```js _.partition([1, 2, 3], function(n) { return n % 2; }); // => [[1, 3], [2]] _.partition([1.2, 2.3, 3.4], function(n) { return this.floor(n) % 2; }, Math); // => [[1.2, 3.4], [2.3]] var users = [ { 'user': 'barney', 'age': 36, 'active': false }, { 'user': 'fred', 'age': 40, 'active': true }, { 'user': 'pebbles', 'age': 1, 'active': false } ]; var mapper = function(array) { return _.pluck(array, 'user'); }; // using the `_.matches` callback shorthand _.map(_.partition(users, { 'age': 1, 'active': false }), mapper); // => [['pebbles'], ['barney', 'fred']] // using the `_.matchesProperty` callback shorthand _.map(_.partition(users, 'active', false), mapper); // => [['barney', 'pebbles'], ['fred']] // using the `_.property` callback shorthand _.map(_.partition(users, 'active'), mapper); // => [['fred'], ['barney', 'pebbles']] ``` * * * ### `_.pluck(collection, path)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6956 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pluck "See the npm package") Gets the property value of `path` from all elements in `collection`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `path` *(Array|string)*: The path of the property to pluck. #### Returns *(Array)*: Returns the property values. #### Example ```js var users = [ { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 } ]; _.pluck(users, 'user'); // => ['barney', 'fred'] var userIndex = _.indexBy(users, 'user'); _.pluck(userIndex, 'age'); // => [36, 40] (iteration order is not guaranteed) ``` * * * ### `_.reduce(collection, [iteratee=_.identity], [accumulator], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L6997 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.reduce "See the npm package") Reduces `collection` to a value which is the accumulated result of running each element in `collection` through `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not provided the first element of `collection` is used as the initial value. The `iteratee` is bound to `thisArg` and invoked with four arguments:
(accumulator, value, index|key, collection).

Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`.

The guarded methods are:
`assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `sortByAll`, and `sortByOrder` #### Aliases *_.foldl, _.inject* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[accumulator]` *(*)*: The initial value. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(*)*: Returns the accumulated value. #### Example ```js _.reduce([1, 2], function(total, n) { return total + n; }); // => 3 _.reduce({ 'a': 1, 'b': 2 }, function(result, n, key) { result[key] = n * 3; return result; }, {}); // => { 'a': 3, 'b': 6 } (iteration order is not guaranteed) ``` * * * ### `_.reduceRight(collection, [iteratee=_.identity], [accumulator], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7021 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.reduceright "See the npm package") This method is like `_.reduce` except that it iterates over elements of `collection` from right to left. #### Aliases *_.foldr* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[accumulator]` *(*)*: The initial value. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(*)*: Returns the accumulated value. #### Example ```js var array = [[0, 1], [2, 3], [4, 5]]; _.reduceRight(array, function(flattened, other) { return flattened.concat(other); }, []); // => [4, 5, 2, 3, 0, 1] ``` * * * ### `_.reject(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7059 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.reject "See the npm package") The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Array)*: Returns the new filtered array. #### Example ```js _.reject([1, 2, 3, 4], function(n) { return n % 2 == 0; }); // => [1, 3] var users = [ { 'user': 'barney', 'age': 36, 'active': false }, { 'user': 'fred', 'age': 40, 'active': true } ]; // using the `_.matches` callback shorthand _.pluck(_.reject(users, { 'age': 40, 'active': true }), 'user'); // => ['barney'] // using the `_.matchesProperty` callback shorthand _.pluck(_.reject(users, 'active', false), 'user'); // => ['fred'] // using the `_.property` callback shorthand _.pluck(_.reject(users, 'active'), 'user'); // => ['barney'] ``` * * * ### `_.sample(collection, [n])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7085 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sample "See the npm package") Gets a random element or `n` random elements from a collection. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to sample. 2. `[n]` *(number)*: The number of elements to sample. #### Returns *(*)*: Returns the random sample(s). #### Example ```js _.sample([1, 2, 3, 4]); // => 2 _.sample([1, 2, 3, 4], 2); // => [3, 1] ``` * * * ### `_.shuffle(collection)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7122 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.shuffle "See the npm package") Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle). #### Arguments 1. `collection` *(Array|Object|string)*: The collection to shuffle. #### Returns *(Array)*: Returns the new shuffled array. #### Example ```js _.shuffle([1, 2, 3, 4]); // => [4, 1, 3, 2] ``` * * * ### `_.size(collection)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7146 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.size "See the npm package") Gets the size of `collection` by returning its length for array-like values or the number of own enumerable properties for objects. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to inspect. #### Returns *(number)*: Returns the size of `collection`. #### Example ```js _.size([1, 2, 3]); // => 3 _.size({ 'a': 1, 'b': 2 }); // => 2 _.size('pebbles'); // => 7 ``` * * * ### `_.some(collection, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7200 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.some "See the npm package") Checks if `predicate` returns truthy for **any** element of `collection`. The function returns as soon as it finds a passing value and does not iterate over the entire collection. The predicate is bound to `thisArg` and invoked with three arguments: (value, index|key, collection).

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Aliases *_.any* #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(boolean)*: Returns `true` if any element passes the predicate check, else `false`. #### Example ```js _.some([null, 0, 'yes', false], Boolean); // => true var users = [ { 'user': 'barney', 'active': true }, { 'user': 'fred', 'active': false } ]; // using the `_.matches` callback shorthand _.some(users, { 'user': 'barney', 'active': false }); // => false // using the `_.matchesProperty` callback shorthand _.some(users, 'active', false); // => true // using the `_.property` callback shorthand _.some(users, 'active'); // => true ``` * * * ### `_.sortBy(collection, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7259 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sortby "See the npm package") Creates an array of elements, sorted in ascending order by the results of running each element in a collection through `iteratee`. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The `iteratee` is bound to `thisArg` and invoked with three arguments:
(value, index|key, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Array)*: Returns the new sorted array. #### Example ```js _.sortBy([1, 2, 3], function(n) { return Math.sin(n); }); // => [3, 1, 2] _.sortBy([1, 2, 3], function(n) { return this.sin(n); }, Math); // => [3, 1, 2] var users = [ { 'user': 'fred' }, { 'user': 'pebbles' }, { 'user': 'barney' } ]; // using the `_.property` callback shorthand _.pluck(_.sortBy(users, 'user'), 'user'); // => ['barney', 'fred', 'pebbles'] ``` * * * ### `_.sortByAll(collection, iteratees)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7310 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sortbyall "See the npm package") This method is like `_.sortBy` except that it can sort by multiple iteratees or property names.

If a property name is provided for an iteratee the created `_.property` style callback returns the property value of the given element.

If an object is provided for an iteratee the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `iteratees` *(...(Function|Function[]|Object|Object[]|string|string[])*: The iteratees to sort by, specified as individual values or arrays of values. #### Returns *(Array)*: Returns the new sorted array. #### Example ```js var users = [ { 'user': 'fred', 'age': 48 }, { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 42 }, { 'user': 'barney', 'age': 34 } ]; _.map(_.sortByAll(users, ['user', 'age']), _.values); // => [['barney', 34], ['barney', 36], ['fred', 42], ['fred', 48]] _.map(_.sortByAll(users, 'user', function(chr) { return Math.floor(chr.age / 10); }), _.values); // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]] ``` * * * ### `_.sortByOrder(collection, iteratees, [orders])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7355 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sortbyorder "See the npm package") This method is like `_.sortByAll` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, a value is sorted in ascending order if its corresponding order is "asc", and descending if "desc".

If a property name is provided for an iteratee the created `_.property` style callback returns the property value of the given element.

If an object is provided for an iteratee the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `iteratees` *(Function[]|Object[]|string[])*: The iteratees to sort by. 3. `[orders]` *(boolean[])*: The sort orders of `iteratees`. #### Returns *(Array)*: Returns the new sorted array. #### Example ```js var users = [ { 'user': 'fred', 'age': 48 }, { 'user': 'barney', 'age': 34 }, { 'user': 'fred', 'age': 42 }, { 'user': 'barney', 'age': 36 } ]; // sort by `user` in ascending order and by `age` in descending order _.map(_.sortByOrder(users, ['user', 'age'], ['asc', 'desc']), _.values); // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]] ``` * * * ### `_.where(collection, source)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7400 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.where "See the npm package") Performs a deep comparison between each element in `collection` and the source object, returning an array of all elements that have equivalent property values.

**Note:** This method supports comparing arrays, booleans, `Date` objects, numbers, `Object` objects, regexes, and strings. Objects are compared by their own, not inherited, enumerable properties. For comparing a single own or inherited property value see `_.matchesProperty`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to search. 2. `source` *(Object)*: The object of property values to match. #### Returns *(Array)*: Returns the new filtered array. #### Example ```js var users = [ { 'user': 'barney', 'age': 36, 'active': false, 'pets': ['hoppy'] }, { 'user': 'fred', 'age': 40, 'active': true, 'pets': ['baby puss', 'dino'] } ]; _.pluck(_.where(users, { 'age': 36, 'active': false }), 'user'); // => ['barney'] _.pluck(_.where(users, { 'pets': ['dino'] }), 'user'); // => ['fred'] ``` * * * ## `“Date” Methods` ### `_.now` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7420 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.now "See the npm package") Gets the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC). #### Example ```js _.defer(function(stamp) { console.log(_.now() - stamp); }, _.now()); // => logs the number of milliseconds it took for the deferred function to be invoked ``` * * * ## `“Function” Methods` ### `_.after(n, func)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7449 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.after "See the npm package") The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times. #### Arguments 1. `n` *(number)*: The number of calls before `func` is invoked. 2. `func` *(Function)*: The function to restrict. #### Returns *(Function)*: Returns the new restricted function. #### Example ```js var saves = ['profile', 'settings']; var done = _.after(saves.length, function() { console.log('done saving!'); }); _.forEach(saves, function(type) { asyncSave({ 'type': type, 'complete': done }); }); // => logs 'done saving!' after the two async saves have completed ``` * * * ### `_.ary(func, [n=func.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7483 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.ary "See the npm package") Creates a function that accepts up to `n` arguments ignoring any additional arguments. #### Arguments 1. `func` *(Function)*: The function to cap arguments for. 2. `[n=func.length]` *(number)*: The arity cap. #### Returns *(Function)*: Returns the new function. #### Example ```js _.map(['6', '8', '10'], _.ary(parseInt, 1)); // => [6, 8, 10] ``` * * * ### `_.before(n, func)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7507 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.before "See the npm package") Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation. #### Arguments 1. `n` *(number)*: The number of calls at which `func` is no longer invoked. 2. `func` *(Function)*: The function to restrict. #### Returns *(Function)*: Returns the new restricted function. #### Example ```js jQuery('#add').on('click', _.before(5, addContactToList)); // => allows adding up to 4 contacts to the list ``` * * * ### `_.bind(func, thisArg, [partials])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7564 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.bind "See the npm package") Creates a function that invokes `func` with the `this` binding of `thisArg` and prepends any additional `_.bind` arguments to those provided to the bound function.

The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

**Note:** Unlike native `Function#bind` this method does not set the "length" property of bound functions. #### Arguments 1. `func` *(Function)*: The function to bind. 2. `thisArg` *(*)*: The `this` binding of `func`. 3. `[partials]` *(...*)*: The arguments to be partially applied. #### Returns *(Function)*: Returns the new bound function. #### Example ```js var greet = function(greeting, punctuation) { return greeting + ' ' + this.user + punctuation; }; var object = { 'user': 'fred' }; var bound = _.bind(greet, object, 'hi'); bound('!'); // => 'hi fred!' // using placeholders var bound = _.bind(greet, object, _, '!'); bound('hi'); // => 'hi fred!' ``` * * * ### `_.bindAll(object, [methodNames])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7601 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.bindall "See the npm package") Binds methods of an object to the object itself, overwriting the existing method. Method names may be specified as individual arguments or as arrays of method names. If no method names are provided all enumerable function properties, own and inherited, of `object` are bound.

**Note:** This method does not set the "length" property of bound functions. #### Arguments 1. `object` *(Object)*: The object to bind and assign the bound methods to. 2. `[methodNames]` *(...(string|string[])*: The object method names to bind, specified as individual method names or arrays of method names. #### Returns *(Object)*: Returns `object`. #### Example ```js var view = { 'label': 'docs', 'onClick': function() { console.log('clicked ' + this.label); } }; _.bindAll(view); jQuery('#docs').on('click', view.onClick); // => logs 'clicked docs' when the element is clicked ``` * * * ### `_.bindKey(object, key, [partials])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7658 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.bindkey "See the npm package") Creates a function that invokes the method at `object[key]` and prepends any additional `_.bindKey` arguments to those provided to the bound function.

This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details.

The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. #### Arguments 1. `object` *(Object)*: The object the method belongs to. 2. `key` *(string)*: The key of the method. 3. `[partials]` *(...*)*: The arguments to be partially applied. #### Returns *(Function)*: Returns the new bound function. #### Example ```js var object = { 'user': 'fred', 'greet': function(greeting, punctuation) { return greeting + ' ' + this.user + punctuation; } }; var bound = _.bindKey(object, 'greet', 'hi'); bound('!'); // => 'hi fred!' object.greet = function(greeting, punctuation) { return greeting + 'ya ' + this.user + punctuation; }; bound('!'); // => 'hiya fred!' // using placeholders var bound = _.bindKey(object, 'greet', _, '!'); bound('hi'); // => 'hiya fred!' ``` * * * ### `_.curry(func, [arity=func.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7707 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.curry "See the npm package") Creates a function that accepts one or more arguments of `func` that when called either invokes `func` returning its result, if all `func` arguments have been provided, or returns a function that accepts one or more of the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient.

The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments.

**Note:** This method does not set the "length" property of curried functions. #### Arguments 1. `func` *(Function)*: The function to curry. 2. `[arity=func.length]` *(number)*: The arity of `func`. #### Returns *(Function)*: Returns the new curried function. #### Example ```js var abc = function(a, b, c) { return [a, b, c]; }; var curried = _.curry(abc); curried(1)(2)(3); // => [1, 2, 3] curried(1, 2)(3); // => [1, 2, 3] curried(1, 2, 3); // => [1, 2, 3] // using placeholders curried(1)(_, 3)(2); // => [1, 2, 3] ``` * * * ### `_.curryRight(func, [arity=func.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7746 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.curryright "See the npm package") This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`.

The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments.

**Note:** This method does not set the "length" property of curried functions. #### Arguments 1. `func` *(Function)*: The function to curry. 2. `[arity=func.length]` *(number)*: The arity of `func`. #### Returns *(Function)*: Returns the new curried function. #### Example ```js var abc = function(a, b, c) { return [a, b, c]; }; var curried = _.curryRight(abc); curried(3)(2)(1); // => [1, 2, 3] curried(2, 3)(1); // => [1, 2, 3] curried(1, 2, 3); // => [1, 2, 3] // using placeholders curried(3)(1, _)(2); // => [1, 2, 3] ``` * * * ### `_.debounce(func, [wait=0], [options])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7811 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.debounce "See the npm package") Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed invocations. Provide an options object to indicate that `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. Subsequent calls to the debounced function return the result of the last `func` invocation.

**Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the the debounced function is invoked more than once during the `wait` timeout.

See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) for details over the differences between `_.debounce` and `_.throttle`. #### Arguments 1. `func` *(Function)*: The function to debounce. 2. `[wait=0]` *(number)*: The number of milliseconds to delay. 3. `[options]` *(Object)*: The options object. 4. `[options.leading=false]` *(boolean)*: Specify invoking on the leading edge of the timeout. 5. `[options.maxWait]` *(number)*: The maximum time `func` is allowed to be delayed before it's invoked. 6. `[options.trailing=true]` *(boolean)*: Specify invoking on the trailing edge of the timeout. #### Returns *(Function)*: Returns the new debounced function. #### Example ```js // avoid costly calculations while the window size is in flux jQuery(window).on('resize', _.debounce(calculateLayout, 150)); // invoke `sendMail` when the click event is fired, debouncing subsequent calls jQuery('#postbox').on('click', _.debounce(sendMail, 300, { 'leading': true, 'trailing': false })); // ensure `batchLog` is invoked once after 1 second of debounced calls var source = new EventSource('/stream'); jQuery(source).on('message', _.debounce(batchLog, 250, { 'maxWait': 1000 })); // cancel a debounced call var todoChanges = _.debounce(batchLog, 1000); Object.observe(models.todo, todoChanges); Object.observe(models, function(changes) { if (_.find(changes, { 'user': 'todo', 'type': 'delete'})) { todoChanges.cancel(); } }, ['delete']); // ...at some point `models.todo` is changed models.todo.completed = true; // ...before 1 second has passed `models.todo` is deleted // which cancels the debounced `todoChanges` call delete models.todo; ``` * * * ### `_.defer(func, [args])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7936 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.defer "See the npm package") Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked. #### Arguments 1. `func` *(Function)*: The function to defer. 2. `[args]` *(...*)*: The arguments to invoke the function with. #### Returns *(number)*: Returns the timer id. #### Example ```js _.defer(function(text) { console.log(text); }, 'deferred'); // logs 'deferred' after one or more milliseconds ``` * * * ### `_.delay(func, wait, [args])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7958 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.delay "See the npm package") Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked. #### Arguments 1. `func` *(Function)*: The function to delay. 2. `wait` *(number)*: The number of milliseconds to delay invocation. 3. `[args]` *(...*)*: The arguments to invoke the function with. #### Returns *(number)*: Returns the timer id. #### Example ```js _.delay(function(text) { console.log(text); }, 1000, 'later'); // => logs 'later' after one second ``` * * * ### `_.flow([funcs])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L7982 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.flow "See the npm package") Creates a function that returns the result of invoking the provided functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous. #### Arguments 1. `[funcs]` *(...Function)*: Functions to invoke. #### Returns *(Function)*: Returns the new function. #### Example ```js function square(n) { return n * n; } var addSquare = _.flow(_.add, square); addSquare(1, 2); // => 9 ``` * * * ### `_.flowRight([funcs])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8004 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.flowright "See the npm package") This method is like `_.flow` except that it creates a function that invokes the provided functions from right to left. #### Aliases *_.backflow, _.compose* #### Arguments 1. `[funcs]` *(...Function)*: Functions to invoke. #### Returns *(Function)*: Returns the new function. #### Example ```js function square(n) { return n * n; } var addSquare = _.flowRight(square, _.add); addSquare(1, 2); // => 9 ``` * * * ### `_.memoize(func, [resolver])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8057 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.memoize "See the npm package") Creates a function that memoizes the result of `func`. If `resolver` is provided it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is coerced to a string and used as the cache key. The `func` is invoked with the `this` binding of the memoized function.

**Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/6.0/#sec-properties-of-the-map-prototype-object) method interface of `get`, `has`, and `set`. #### Arguments 1. `func` *(Function)*: The function to have its output memoized. 2. `[resolver]` *(Function)*: The function to resolve the cache key. #### Returns *(Function)*: Returns the new memoizing function. #### Example ```js var upperCase = _.memoize(function(string) { return string.toUpperCase(); }); upperCase('fred'); // => 'FRED' // modifying the result cache upperCase.cache.set('fred', 'BARNEY'); upperCase('fred'); // => 'BARNEY' // replacing `_.memoize.Cache` var object = { 'user': 'fred' }; var other = { 'user': 'barney' }; var identity = _.memoize(_.identity); identity(object); // => { 'user': 'fred' } identity(other); // => { 'user': 'fred' } _.memoize.Cache = WeakMap; var identity = _.memoize(_.identity); identity(object); // => { 'user': 'fred' } identity(other); // => { 'user': 'barney' } ``` * * * ### `_.modArgs(func, [transforms])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8108 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.modargs "See the npm package") Creates a function that runs each argument through a corresponding transform function. #### Arguments 1. `func` *(Function)*: The function to wrap. 2. `[transforms]` *(...(Function|Function[])*: The functions to transform arguments, specified as individual functions or arrays of functions. #### Returns *(Function)*: Returns the new function. #### Example ```js function doubled(n) { return n * 2; } function square(n) { return n * n; } var modded = _.modArgs(function(x, y) { return [x, y]; }, square, doubled); modded(1, 2); // => [1, 4] modded(5, 10); // => [25, 20] ``` * * * ### `_.negate(predicate)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8142 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.negate "See the npm package") Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function. #### Arguments 1. `predicate` *(Function)*: The predicate to negate. #### Returns *(Function)*: Returns the new function. #### Example ```js function isEven(n) { return n % 2 == 0; } _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven)); // => [1, 3, 5] ``` * * * ### `_.once(func)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8168 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.once "See the npm package") Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first call. The `func` is invoked with the `this` binding and arguments of the created function. #### Arguments 1. `func` *(Function)*: The function to restrict. #### Returns *(Function)*: Returns the new restricted function. #### Example ```js var initialize = _.once(createApplication); initialize(); initialize(); // `initialize` invokes `createApplication` once ``` * * * ### `_.partial(func, [partials])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8204 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.partial "See the npm package") Creates a function that invokes `func` with `partial` arguments prepended to those provided to the new function. This method is like `_.bind` except it does **not** alter the `this` binding.

The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

**Note:** This method does not set the "length" property of partially applied functions. #### Arguments 1. `func` *(Function)*: The function to partially apply arguments to. 2. `[partials]` *(...*)*: The arguments to be partially applied. #### Returns *(Function)*: Returns the new partially applied function. #### Example ```js var greet = function(greeting, name) { return greeting + ' ' + name; }; var sayHelloTo = _.partial(greet, 'hello'); sayHelloTo('fred'); // => 'hello fred' // using placeholders var greetFred = _.partial(greet, _, 'fred'); greetFred('hi'); // => 'hi fred' ``` * * * ### `_.partialRight(func, [partials])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8237 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.partialright "See the npm package") This method is like `_.partial` except that partially applied arguments are appended to those provided to the new function.

The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

**Note:** This method does not set the "length" property of partially applied functions. #### Arguments 1. `func` *(Function)*: The function to partially apply arguments to. 2. `[partials]` *(...*)*: The arguments to be partially applied. #### Returns *(Function)*: Returns the new partially applied function. #### Example ```js var greet = function(greeting, name) { return greeting + ' ' + name; }; var greetFred = _.partialRight(greet, 'fred'); greetFred('hi'); // => 'hi fred' // using placeholders var sayHelloTo = _.partialRight(greet, 'hello', _); sayHelloTo('fred'); // => 'hello fred' ``` * * * ### `_.rearg(func, indexes)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8267 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.rearg "See the npm package") Creates a function that invokes `func` with arguments arranged according to the specified indexes where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on. #### Arguments 1. `func` *(Function)*: The function to rearrange arguments for. 2. `indexes` *(...(number|number[])*: The arranged argument indexes, specified as individual indexes or arrays of indexes. #### Returns *(Function)*: Returns the new function. #### Example ```js var rearged = _.rearg(function(a, b, c) { return [a, b, c]; }, 2, 0, 1); rearged('b', 'c', 'a') // => ['a', 'b', 'c'] var map = _.rearg(_.map, [1, 0]); map(function(n) { return n * 3; }, [1, 2, 3]); // => [3, 6, 9] ``` * * * ### `_.restParam(func, [start=func.length-1])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8293 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.restparam "See the npm package") Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array.

**Note:** This method is based on the [rest parameter](https://developer.mozilla.org/Web/JavaScript/Reference/Functions/rest_parameters). #### Arguments 1. `func` *(Function)*: The function to apply a rest parameter to. 2. `[start=func.length-1]` *(number)*: The start position of the rest parameter. #### Returns *(Function)*: Returns the new function. #### Example ```js var say = _.restParam(function(what, names) { return what + ' ' + _.initial(names).join(', ') + (_.size(names) > 1 ? ', & ' : '') + _.last(names); }); say('hello', 'fred', 'barney', 'pebbles'); // => 'hello fred, barney, & pebbles' ``` * * * ### `_.spread(func)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8353 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.spread "See the npm package") Creates a function that invokes `func` with the `this` binding of the created function and an array of arguments much like [`Function#apply`](https://es5.github.io/#x15.3.4.3).

**Note:** This method is based on the [spread operator](https://developer.mozilla.org/Web/JavaScript/Reference/Operators/Spread_operator). #### Arguments 1. `func` *(Function)*: The function to spread arguments over. #### Returns *(Function)*: Returns the new function. #### Example ```js var say = _.spread(function(who, what) { return who + ' says ' + what; }); say(['fred', 'hello']); // => 'fred says hello' // with a Promise var numbers = Promise.all([ Promise.resolve(40), Promise.resolve(36) ]); numbers.then(_.spread(function(x, y) { return x + y; })); // => a Promise of 76 ``` * * * ### `_.throttle(func, [wait=0], [options])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8401 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.throttle "See the npm package") Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed invocations. Provide an options object to indicate that `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. Subsequent calls to the throttled function return the result of the last `func` call.

**Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the the throttled function is invoked more than once during the `wait` timeout.

See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) for details over the differences between `_.throttle` and `_.debounce`. #### Arguments 1. `func` *(Function)*: The function to throttle. 2. `[wait=0]` *(number)*: The number of milliseconds to throttle invocations to. 3. `[options]` *(Object)*: The options object. 4. `[options.leading=true]` *(boolean)*: Specify invoking on the leading edge of the timeout. 5. `[options.trailing=true]` *(boolean)*: Specify invoking on the trailing edge of the timeout. #### Returns *(Function)*: Returns the new throttled function. #### Example ```js // avoid excessively updating the position while scrolling jQuery(window).on('scroll', _.throttle(updatePosition, 100)); // invoke `renewToken` when the click event is fired, but not more than once every 5 minutes jQuery('.interactive').on('click', _.throttle(renewToken, 300000, { 'trailing': false })); // cancel a trailing throttled call jQuery(window).on('popstate', throttled.cancel); ``` * * * ### `_.wrap(value, wrapper)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8438 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.wrap "See the npm package") Creates a function that provides `value` to the wrapper function as its first argument. Any additional arguments provided to the function are appended to those provided to the wrapper function. The wrapper is invoked with the `this` binding of the created function. #### Arguments 1. `value` *(*)*: The value to wrap. 2. `wrapper` *(Function)*: The wrapper function. #### Returns *(Function)*: Returns the new function. #### Example ```js var p = _.wrap(_.escape, function(func, text) { return '

' + func(text) + '

'; }); p('fred, barney, & pebbles'); // => '

fred, barney, & pebbles

' ``` * * * ## `“Lang” Methods` ### `_.clone(value, [isDeep], [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8496 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.clone "See the npm package") Creates a clone of `value`. If `isDeep` is `true` nested objects are cloned, otherwise they are assigned by reference. If `customizer` is provided it's invoked to produce the cloned values. If `customizer` returns `undefined` cloning is handled by the method instead. The `customizer` is bound to `thisArg` and invoked with up to three argument; (value [, index|key, object]).

**Note:** This method is loosely based on the [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). The enumerable properties of `arguments` objects and objects created by constructors other than `Object` are cloned to plain `Object` objects. An empty object is returned for uncloneable values such as functions, DOM nodes, Maps, Sets, and WeakMaps. #### Arguments 1. `value` *(*)*: The value to clone. 2. `[isDeep]` *(boolean)*: Specify a deep clone. 3. `[customizer]` *(Function)*: The function to customize cloning values. 4. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(*)*: Returns the cloned value. #### Example ```js var users = [ { 'user': 'barney' }, { 'user': 'fred' } ]; var shallow = _.clone(users); shallow[0] === users[0]; // => true var deep = _.clone(users, true); deep[0] === users[0]; // => false // using a customizer callback var el = _.clone(document.body, function(value) { if (_.isElement(value)) { return value.cloneNode(false); } }); el === document.body // => false el.nodeName // => BODY el.childNodes.length; // => 0 ``` * * * ### `_.cloneDeep(value, [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8555 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.clonedeep "See the npm package") Creates a deep clone of `value`. If `customizer` is provided it's invoked to produce the cloned values. If `customizer` returns `undefined` cloning is handled by the method instead. The `customizer` is bound to `thisArg` and invoked with up to three argument; (value [, index|key, object]).

**Note:** This method is loosely based on the [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). The enumerable properties of `arguments` objects and objects created by constructors other than `Object` are cloned to plain `Object` objects. An empty object is returned for uncloneable values such as functions, DOM nodes, Maps, Sets, and WeakMaps. #### Arguments 1. `value` *(*)*: The value to deep clone. 2. `[customizer]` *(Function)*: The function to customize cloning values. 3. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(*)*: Returns the deep cloned value. #### Example ```js var users = [ { 'user': 'barney' }, { 'user': 'fred' } ]; var deep = _.cloneDeep(users); deep[0] === users[0]; // => false // using a customizer callback var el = _.cloneDeep(document.body, function(value) { if (_.isElement(value)) { return value.cloneNode(true); } }); el === document.body // => false el.nodeName // => BODY el.childNodes.length; // => 20 ``` * * * ### `_.gt(value, other)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8581 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.gt "See the npm package") Checks if `value` is greater than `other`. #### Arguments 1. `value` *(*)*: The value to compare. 2. `other` *(*)*: The other value to compare. #### Returns *(boolean)*: Returns `true` if `value` is greater than `other`, else `false`. #### Example ```js _.gt(3, 1); // => true _.gt(3, 3); // => false _.gt(1, 3); // => false ``` * * * ### `_.gte(value, other)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8605 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.gte "See the npm package") Checks if `value` is greater than or equal to `other`. #### Arguments 1. `value` *(*)*: The value to compare. 2. `other` *(*)*: The other value to compare. #### Returns *(boolean)*: Returns `true` if `value` is greater than or equal to `other`, else `false`. #### Example ```js _.gte(3, 1); // => true _.gte(3, 3); // => true _.gte(1, 3); // => false ``` * * * ### `_.isArguments(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8625 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isarguments "See the npm package") Checks if `value` is classified as an `arguments` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isArguments(function() { return arguments; }()); // => true _.isArguments([1, 2, 3]); // => false ``` * * * ### `_.isArray(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8646 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isarray "See the npm package") Checks if `value` is classified as an `Array` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isArray([1, 2, 3]); // => true _.isArray(function() { return arguments; }()); // => false ``` * * * ### `_.isBoolean(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8666 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isboolean "See the npm package") Checks if `value` is classified as a boolean primitive or object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isBoolean(false); // => true _.isBoolean(null); // => false ``` * * * ### `_.isDate(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8686 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isdate "See the npm package") Checks if `value` is classified as a `Date` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isDate(new Date); // => true _.isDate('Mon April 23 2012'); // => false ``` * * * ### `_.isElement(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8706 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.iselement "See the npm package") Checks if `value` is a DOM element. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is a DOM element, else `false`. #### Example ```js _.isElement(document.body); // => true _.isElement(''); // => false ``` * * * ### `_.isEmpty(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8737 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isempty "See the npm package") Checks if `value` is empty. A value is considered empty unless it's an `arguments` object, array, string, or jQuery-like collection with a length greater than `0` or an object with own enumerable properties. #### Arguments 1. `value` *(Array|Object|string)*: The value to inspect. #### Returns *(boolean)*: Returns `true` if `value` is empty, else `false`. #### Example ```js _.isEmpty(null); // => true _.isEmpty(true); // => true _.isEmpty(1); // => true _.isEmpty([1, 2, 3]); // => false _.isEmpty({ 'a': 1 }); // => false ``` * * * ### `_.isEqual(value, other, [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8792 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isequal "See the npm package") Performs a deep comparison between two values to determine if they are equivalent. If `customizer` is provided it's invoked to compare values. If `customizer` returns `undefined` comparisons are handled by the method instead. The `customizer` is bound to `thisArg` and invoked with up to three arguments: (value, other [, index|key]).

**Note:** This method supports comparing arrays, booleans, `Date` objects, numbers, `Object` objects, regexes, and strings. Objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are **not** supported. Provide a customizer function to extend support for comparing other values. #### Aliases *_.eq* #### Arguments 1. `value` *(*)*: The value to compare. 2. `other` *(*)*: The other value to compare. 3. `[customizer]` *(Function)*: The function to customize value comparisons. 4. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(boolean)*: Returns `true` if the values are equivalent, else `false`. #### Example ```js var object = { 'user': 'fred' }; var other = { 'user': 'fred' }; object == other; // => false _.isEqual(object, other); // => true // using a customizer callback var array = ['hello', 'goodbye']; var other = ['hi', 'goodbye']; _.isEqual(array, other, function(value, other) { if (_.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/)) { return true; } }); // => true ``` * * * ### `_.isError(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8815 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.iserror "See the npm package") Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is an error object, else `false`. #### Example ```js _.isError(new Error); // => true _.isError(Error); // => false ``` * * * ### `_.isFinite(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8846 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isfinite "See the npm package") Checks if `value` is a finite primitive number.

**Note:** This method is based on [`Number.isFinite`](http://ecma-international.org/ecma-262/6.0/#sec-number.isfinite). #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is a finite number, else `false`. #### Example ```js _.isFinite(10); // => true _.isFinite('10'); // => false _.isFinite(true); // => false _.isFinite(Object(10)); // => false _.isFinite(Infinity); // => false ``` * * * ### `_.isFunction(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8866 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isfunction "See the npm package") Checks if `value` is classified as a `Function` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isFunction(_); // => true _.isFunction(/abc/); // => false ``` * * * ### `_.isMatch(object, source, [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8939 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.ismatch "See the npm package") Performs a deep comparison between `object` and `source` to determine if `object` contains equivalent property values. If `customizer` is provided it's invoked to compare values. If `customizer` returns `undefined` comparisons are handled by the method instead. The `customizer` is bound to `thisArg` and invoked with three arguments: (value, other, index|key).

**Note:** This method supports comparing properties of arrays, booleans, `Date` objects, numbers, `Object` objects, regexes, and strings. Functions and DOM nodes are **not** supported. Provide a customizer function to extend support for comparing other values. #### Arguments 1. `object` *(Object)*: The object to inspect. 2. `source` *(Object)*: The object of property values to match. 3. `[customizer]` *(Function)*: The function to customize value comparisons. 4. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(boolean)*: Returns `true` if `object` is a match, else `false`. #### Example ```js var object = { 'user': 'fred', 'age': 40 }; _.isMatch(object, { 'age': 40 }); // => true _.isMatch(object, { 'age': 36 }); // => false // using a customizer callback var object = { 'greeting': 'hello' }; var source = { 'greeting': 'hi' }; _.isMatch(object, source, function(value, other) { return _.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/) || undefined; }); // => true ``` * * * ### `_.isNaN(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8969 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isnan "See the npm package") Checks if `value` is `NaN`.

**Note:** This method is not the same as [`isNaN`](https://es5.github.io/#x15.1.2.4) which returns `true` for `undefined` and other non-numeric values. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is `NaN`, else `false`. #### Example ```js _.isNaN(NaN); // => true _.isNaN(new Number(NaN)); // => true isNaN(undefined); // => true _.isNaN(undefined); // => false ``` * * * ### `_.isNative(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8991 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isnative "See the npm package") Checks if `value` is a native function. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is a native function, else `false`. #### Example ```js _.isNative(Array.prototype.push); // => true _.isNative(_); // => false ``` * * * ### `_.isNull(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9017 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isnull "See the npm package") Checks if `value` is `null`. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is `null`, else `false`. #### Example ```js _.isNull(null); // => true _.isNull(void 0); // => false ``` * * * ### `_.isNumber(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9043 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isnumber "See the npm package") Checks if `value` is classified as a `Number` primitive or object.

**Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isNumber(8.4); // => true _.isNumber(NaN); // => true _.isNumber('8.4'); // => false ``` * * * ### `_.isObject(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L8893 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isobject "See the npm package") Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is an object, else `false`. #### Example ```js _.isObject({}); // => true _.isObject([1, 2, 3]); // => true _.isObject(1); // => false ``` * * * ### `_.isPlainObject(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9077 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isplainobject "See the npm package") Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.

**Note:** This method assumes objects created by the `Object` constructor have no inherited enumerable properties. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is a plain object, else `false`. #### Example ```js function Foo() { this.a = 1; } _.isPlainObject(new Foo); // => false _.isPlainObject([1, 2, 3]); // => false _.isPlainObject({ 'x': 0, 'y': 0 }); // => true _.isPlainObject(Object.create(null)); // => true ``` * * * ### `_.isRegExp(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9121 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isregexp "See the npm package") Checks if `value` is classified as a `RegExp` object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isRegExp(/abc/); // => true _.isRegExp('/abc/'); // => false ``` * * * ### `_.isString(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9141 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isstring "See the npm package") Checks if `value` is classified as a `String` primitive or object. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isString('abc'); // => true _.isString(1); // => false ``` * * * ### `_.isTypedArray(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9161 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.istypedarray "See the npm package") Checks if `value` is classified as a typed array. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is correctly classified, else `false`. #### Example ```js _.isTypedArray(new Uint8Array); // => true _.isTypedArray([]); // => false ``` * * * ### `_.isUndefined(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9181 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.isundefined "See the npm package") Checks if `value` is `undefined`. #### Arguments 1. `value` *(*)*: The value to check. #### Returns *(boolean)*: Returns `true` if `value` is `undefined`, else `false`. #### Example ```js _.isUndefined(void 0); // => true _.isUndefined(null); // => false ``` * * * ### `_.lt(value, other)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9205 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.lt "See the npm package") Checks if `value` is less than `other`. #### Arguments 1. `value` *(*)*: The value to compare. 2. `other` *(*)*: The other value to compare. #### Returns *(boolean)*: Returns `true` if `value` is less than `other`, else `false`. #### Example ```js _.lt(1, 3); // => true _.lt(3, 3); // => false _.lt(3, 1); // => false ``` * * * ### `_.lte(value, other)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9229 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.lte "See the npm package") Checks if `value` is less than or equal to `other`. #### Arguments 1. `value` *(*)*: The value to compare. 2. `other` *(*)*: The other value to compare. #### Returns *(boolean)*: Returns `true` if `value` is less than or equal to `other`, else `false`. #### Example ```js _.lte(1, 3); // => true _.lte(3, 3); // => true _.lte(3, 1); // => false ``` * * * ### `_.toArray(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9248 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.toarray "See the npm package") Converts `value` to an array. #### Arguments 1. `value` *(*)*: The value to convert. #### Returns *(Array)*: Returns the converted array. #### Example ```js (function() { return _.toArray(arguments).slice(1); }(1, 2, 3)); // => [2, 3] ``` * * * ### `_.toPlainObject(value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9284 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.toplainobject "See the npm package") Converts `value` to a plain object flattening inherited enumerable properties of `value` to own properties of the plain object. #### Arguments 1. `value` *(*)*: The value to convert. #### Returns *(Object)*: Returns the converted plain object. #### Example ```js function Foo() { this.b = 2; } Foo.prototype.c = 3; _.assign({ 'a': 1 }, new Foo); // => { 'a': 1, 'b': 2 } _.assign({ 'a': 1 }, _.toPlainObject(new Foo)); // => { 'a': 1, 'b': 2, 'c': 3 } ``` * * * ## `“Math” Methods` ### `_.add(augend, addend)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11803 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.add "See the npm package") Adds two numbers. #### Arguments 1. `augend` *(number)*: The first number to add. 2. `addend` *(number)*: The second number to add. #### Returns *(number)*: Returns the sum. #### Example ```js _.add(6, 4); // => 10 ``` * * * ### `_.ceil(n, [precision=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11827 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.ceil "See the npm package") Calculates `n` rounded up to `precision`. #### Arguments 1. `n` *(number)*: The number to round up. 2. `[precision=0]` *(number)*: The precision to round up to. #### Returns *(number)*: Returns the rounded up number. #### Example ```js _.ceil(4.006); // => 5 _.ceil(6.004, 2); // => 6.01 _.ceil(6040, -2); // => 6100 ``` * * * ### `_.floor(n, [precision=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11849 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.floor "See the npm package") Calculates `n` rounded down to `precision`. #### Arguments 1. `n` *(number)*: The number to round down. 2. `[precision=0]` *(number)*: The precision to round down to. #### Returns *(number)*: Returns the rounded down number. #### Example ```js _.floor(4.006); // => 4 _.floor(0.046, 2); // => 0.04 _.floor(4060, -2); // => 4000 ``` * * * ### `_.max(collection, [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11898 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.max "See the npm package") Gets the maximum value of `collection`. If `collection` is empty or falsey `-Infinity` is returned. If an iteratee function is provided it's invoked for each value in `collection` to generate the criterion by which the value is ranked. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, index, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(*)*: Returns the maximum value. #### Example ```js _.max([4, 2, 8, 6]); // => 8 _.max([]); // => -Infinity var users = [ { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 } ]; _.max(users, function(chr) { return chr.age; }); // => { 'user': 'fred', 'age': 40 } // using the `_.property` callback shorthand _.max(users, 'age'); // => { 'user': 'fred', 'age': 40 } ``` * * * ### `_.min(collection, [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11947 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.min "See the npm package") Gets the minimum value of `collection`. If `collection` is empty or falsey `Infinity` is returned. If an iteratee function is provided it's invoked for each value in `collection` to generate the criterion by which the value is ranked. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, index, collection).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(*)*: Returns the minimum value. #### Example ```js _.min([4, 2, 8, 6]); // => 2 _.min([]); // => Infinity var users = [ { 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 } ]; _.min(users, function(chr) { return chr.age; }); // => { 'user': 'barney', 'age': 36 } // using the `_.property` callback shorthand _.min(users, 'age'); // => { 'user': 'barney', 'age': 36 } ``` * * * ### `_.round(n, [precision=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L11969 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.round "See the npm package") Calculates `n` rounded to `precision`. #### Arguments 1. `n` *(number)*: The number to round. 2. `[precision=0]` *(number)*: The precision to round to. #### Returns *(number)*: Returns the rounded number. #### Example ```js _.round(4.006); // => 4 _.round(4.006, 2); // => 4.01 _.round(4060, -2); // => 4100 ``` * * * ### `_.sum(collection, [iteratee], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L12003 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.sum "See the npm package") Gets the sum of the values in `collection`. #### Arguments 1. `collection` *(Array|Object|string)*: The collection to iterate over. 2. `[iteratee]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(number)*: Returns the sum. #### Example ```js _.sum([4, 6]); // => 10 _.sum({ 'a': 4, 'b': 6 }); // => 10 var objects = [ { 'n': 4 }, { 'n': 6 } ]; _.sum(objects, function(object) { return object.n; }); // => 10 // using the `_.property` callback shorthand _.sum(objects, 'n'); // => 10 ``` * * * ## `“Number” Methods` ### `_.inRange(n, [start=0], end)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10321 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.inrange "See the npm package") Checks if `n` is between `start` and up to but not including, `end`. If `end` is not specified it's set to `start` with `start` then set to `0`. #### Arguments 1. `n` *(number)*: The number to check. 2. `[start=0]` *(number)*: The start of the range. 3. `end` *(number)*: The end of the range. #### Returns *(boolean)*: Returns `true` if `n` is in the range, else `false`. #### Example ```js _.inRange(3, 2, 4); // => true _.inRange(4, 8); // => true _.inRange(4, 2); // => false _.inRange(2, 2); // => false _.inRange(1.2, 2); // => true _.inRange(5.2, 4); // => false ``` * * * ### `_.random([min=0], [max=1], [floating])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10359 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.random "See the npm package") Produces a random number between `min` and `max` (inclusive). If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `min` or `max` are floats, a floating-point number is returned instead of an integer. #### Arguments 1. `[min=0]` *(number)*: The minimum possible value. 2. `[max=1]` *(number)*: The maximum possible value. 3. `[floating]` *(boolean)*: Specify returning a floating-point number. #### Returns *(number)*: Returns the random number. #### Example ```js _.random(0, 5); // => an integer between 0 and 5 _.random(5); // => also an integer between 0 and 5 _.random(5, true); // => a floating-point number between 0 and 5 _.random(1.2, 5.2); // => a floating-point number between 1.2 and 5.2 ``` * * * ## `“Object” Methods` ### `_.assign(object, [sources], [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9372 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.assign "See the npm package") Assigns own enumerable properties of source object(s) to the destination object. Subsequent sources overwrite property assignments of previous sources. If `customizer` is provided it's invoked to produce the assigned values. The `customizer` is bound to `thisArg` and invoked with five arguments:
(objectValue, sourceValue, key, object, source).

**Note:** This method mutates `object` and is based on [`Object.assign`](http://ecma-international.org/ecma-262/6.0/#sec-object.assign). #### Aliases *_.extend* #### Arguments 1. `object` *(Object)*: The destination object. 2. `[sources]` *(...Object)*: The source objects. 3. `[customizer]` *(Function)*: The function to customize assigned values. 4. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(Object)*: Returns `object`. #### Example ```js _.assign({ 'user': 'barney' }, { 'age': 40 }, { 'user': 'fred' }); // => { 'user': 'fred', 'age': 40 } // using a customizer callback var defaults = _.partialRight(_.assign, function(value, other) { return _.isUndefined(value) ? other : value; }); defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); // => { 'user': 'barney', 'age': 36 } ``` * * * ### `_.create(prototype, [properties])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9412 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.create "See the npm package") Creates an object that inherits from the given `prototype` object. If a `properties` object is provided its own enumerable properties are assigned to the created object. #### Arguments 1. `prototype` *(Object)*: The object to inherit from. 2. `[properties]` *(Object)*: The properties to assign to the object. #### Returns *(Object)*: Returns the new object. #### Example ```js function Shape() { this.x = 0; this.y = 0; } function Circle() { Shape.call(this); } Circle.prototype = _.create(Shape.prototype, { 'constructor': Circle }); var circle = new Circle; circle instanceof Circle; // => true circle instanceof Shape; // => true ``` * * * ### `_.defaults(object, [sources])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9438 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.defaults "See the npm package") Assigns own enumerable properties of source object(s) to the destination object for all destination properties that resolve to `undefined`. Once a property is set, additional values of the same property are ignored.

**Note:** This method mutates `object`. #### Arguments 1. `object` *(Object)*: The destination object. 2. `[sources]` *(...Object)*: The source objects. #### Returns *(Object)*: Returns `object`. #### Example ```js _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); // => { 'user': 'barney', 'age': 36 } ``` * * * ### `_.defaultsDeep(object, [sources])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9458 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.defaultsdeep "See the npm package") This method is like `_.defaults` except that it recursively assigns default properties.

**Note:** This method mutates `object`. #### Arguments 1. `object` *(Object)*: The destination object. 2. `[sources]` *(...Object)*: The source objects. #### Returns *(Object)*: Returns `object`. #### Example ```js _.defaultsDeep({ 'user': { 'name': 'barney' } }, { 'user': { 'name': 'fred', 'age': 36 } }); // => { 'user': { 'name': 'barney', 'age': 36 } } ``` * * * ### `_.findKey(object, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9508 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findkey "See the npm package") This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `object` *(Object)*: The object to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(string|undefined)*: Returns the key of the matched element, else `undefined`. #### Example ```js var users = { 'barney': { 'age': 36, 'active': true }, 'fred': { 'age': 40, 'active': false }, 'pebbles': { 'age': 1, 'active': true } }; _.findKey(users, function(chr) { return chr.age < 40; }); // => 'barney' (iteration order is not guaranteed) // using the `_.matches` callback shorthand _.findKey(users, { 'age': 1, 'active': true }); // => 'pebbles' // using the `_.matchesProperty` callback shorthand _.findKey(users, 'active', false); // => 'fred' // using the `_.property` callback shorthand _.findKey(users, 'active'); // => 'barney' ``` * * * ### `_.findLastKey(object, [predicate=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9558 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.findlastkey "See the npm package") This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.

If a property name is provided for `predicate` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `predicate` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `object` *(Object)*: The object to search. 2. `[predicate=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(string|undefined)*: Returns the key of the matched element, else `undefined`. #### Example ```js var users = { 'barney': { 'age': 36, 'active': true }, 'fred': { 'age': 40, 'active': false }, 'pebbles': { 'age': 1, 'active': true } }; _.findLastKey(users, function(chr) { return chr.age < 40; }); // => returns `pebbles` assuming `_.findKey` returns `barney` // using the `_.matches` callback shorthand _.findLastKey(users, { 'age': 36, 'active': true }); // => 'barney' // using the `_.matchesProperty` callback shorthand _.findLastKey(users, 'active', false); // => 'fred' // using the `_.property` callback shorthand _.findLastKey(users, 'active'); // => 'pebbles' ``` * * * ### `_.forIn(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9587 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.forin "See the npm package") Iterates over own and inherited enumerable properties of an object invoking `iteratee` for each property. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns `object`. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.forIn(new Foo, function(value, key) { console.log(key); }); // => logs 'a', 'b', and 'c' (iteration order is not guaranteed) ``` * * * ### `_.forInRight(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9614 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.forinright "See the npm package") This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns `object`. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.forInRight(new Foo, function(value, key) { console.log(key); }); // => logs 'c', 'b', and 'a' assuming `_.forIn ` logs 'a', 'b', and 'c' ``` * * * ### `_.forOwn(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9643 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.forown "See the npm package") Iterates over own enumerable properties of an object invoking `iteratee` for each property. The `iteratee` is bound to `thisArg` and invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns `object`. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.forOwn(new Foo, function(value, key) { console.log(key); }); // => logs 'a' and 'b' (iteration order is not guaranteed) ``` * * * ### `_.forOwnRight(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9670 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.forownright "See the npm package") This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns `object`. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.forOwnRight(new Foo, function(value, key) { console.log(key); }); // => logs 'b' and 'a' assuming `_.forOwn` logs 'a' and 'b' ``` * * * ### `_.functions(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9687 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.functions "See the npm package") Creates an array of function property names from all enumerable properties, own and inherited, of `object`. #### Aliases *_.methods* #### Arguments 1. `object` *(Object)*: The object to inspect. #### Returns *(Array)*: Returns the new array of property names. #### Example ```js _.functions(_); // => ['after', 'ary', 'assign', ...] ``` * * * ### `_.get(object, path, [defaultValue])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9715 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.get "See the npm package") Gets the property value at `path` of `object`. If the resolved value is `undefined` the `defaultValue` is used in its place. #### Arguments 1. `object` *(Object)*: The object to query. 2. `path` *(Array|string)*: The path of the property to get. 3. `[defaultValue]` *(*)*: The value returned if the resolved value is `undefined`. #### Returns *(*)*: Returns the resolved value. #### Example ```js var object = { 'a': [{ 'b': { 'c': 3 } }] }; _.get(object, 'a[0].b.c'); // => 3 _.get(object, ['a', '0', 'b', 'c']); // => 3 _.get(object, 'a.b.c', 'default'); // => 'default' ``` * * * ### `_.has(object, path)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9742 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.has "See the npm package") Checks if `path` is a direct property. #### Arguments 1. `object` *(Object)*: The object to query. 2. `path` *(Array|string)*: The path to check. #### Returns *(boolean)*: Returns `true` if `path` is a direct property, else `false`. #### Example ```js var object = { 'a': { 'b': { 'c': 3 } } }; _.has(object, 'a'); // => true _.has(object, 'a.b.c'); // => true _.has(object, ['a', 'b', 'c']); // => true ``` * * * ### `_.invert(object, [multiValue])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9783 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.invert "See the npm package") Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values unless `multiValue` is `true`. #### Arguments 1. `object` *(Object)*: The object to invert. 2. `[multiValue]` *(boolean)*: Allow multiple values per key. #### Returns *(Object)*: Returns the new inverted object. #### Example ```js var object = { 'a': 1, 'b': 2, 'c': 1 }; _.invert(object); // => { '1': 'c', '2': 'b' } // with `multiValue` _.invert(object, true); // => { '1': ['a', 'c'], '2': ['b'] } ``` * * * ### `_.keys(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9837 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.keys "See the npm package") Creates an array of the own enumerable property names of `object`.

**Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/6.0/#sec-object.keys) for more details. #### Arguments 1. `object` *(Object)*: The object to query. #### Returns *(Array)*: Returns the array of property names. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.keys(new Foo); // => ['a', 'b'] (iteration order is not guaranteed) _.keys('hi'); // => ['0', '1'] ``` * * * ### `_.keysIn(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9868 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.keysin "See the npm package") Creates an array of the own and inherited enumerable property names of `object`.

**Note:** Non-object values are coerced to objects. #### Arguments 1. `object` *(Object)*: The object to query. #### Returns *(Array)*: Returns the array of property names. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.keysIn(new Foo); // => ['a', 'b', 'c'] (iteration order is not guaranteed) ``` * * * ### `_.mapKeys(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9945 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.mapkeys "See the npm package") The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable property of `object` through `iteratee`. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns the new mapped object. #### Example ```js _.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) { return key + value; }); // => { 'a1': 1, 'b2': 2 } ``` * * * ### `_.mapValues(object, [iteratee=_.identity], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9988 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.mapvalues "See the npm package") Creates an object with the same keys as `object` and values generated by running each own enumerable property of `object` through `iteratee`. The iteratee function is bound to `thisArg` and invoked with three arguments:
(value, key, object).

If a property name is provided for `iteratee` the created `_.property` style callback returns the property value of the given element.

If a value is also provided for `thisArg` the created `_.matchesProperty` style callback returns `true` for elements that have a matching property value, else `false`.

If an object is provided for `iteratee` the created `_.matches` style callback returns `true` for elements that have the properties of the given object, else `false`. #### Arguments 1. `object` *(Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function|Object|string)*: The function invoked per iteration. 3. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(Object)*: Returns the new mapped object. #### Example ```js _.mapValues({ 'a': 1, 'b': 2 }, function(n) { return n * 3; }); // => { 'a': 3, 'b': 6 } var users = { 'fred': { 'user': 'fred', 'age': 40 }, 'pebbles': { 'user': 'pebbles', 'age': 1 } }; // using the `_.property` callback shorthand _.mapValues(users, 'age'); // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) ``` * * * ### `_.merge(object, [sources], [customizer], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L9338 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.merge "See the npm package") Recursively merges own enumerable properties of the source object(s), that don't resolve to `undefined` into the destination object. Subsequent sources overwrite property assignments of previous sources. If `customizer` is provided it's invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined` merging is handled by the method instead. The `customizer` is bound to `thisArg` and invoked with five arguments: (objectValue, sourceValue, key, object, source). #### Arguments 1. `object` *(Object)*: The destination object. 2. `[sources]` *(...Object)*: The source objects. 3. `[customizer]` *(Function)*: The function to customize assigned values. 4. `[thisArg]` *(*)*: The `this` binding of `customizer`. #### Returns *(Object)*: Returns `object`. #### Example ```js var users = { 'data': [{ 'user': 'barney' }, { 'user': 'fred' }] }; var ages = { 'data': [{ 'age': 36 }, { 'age': 40 }] }; _.merge(users, ages); // => { 'data': [{ 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }] } // using a customizer callback var object = { 'fruits': ['apple'], 'vegetables': ['beet'] }; var other = { 'fruits': ['banana'], 'vegetables': ['carrot'] }; _.merge(object, other, function(a, b) { if (_.isArray(a)) { return a.concat(b); } }); // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot'] } ``` * * * ### `_.omit(object, [predicate], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10013 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.omit "See the npm package") The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable properties of `object` that are not omitted. #### Arguments 1. `object` *(Object)*: The source object. 2. `[predicate]` *(Function|...(string|string[])*: The function invoked per iteration or property names to omit, specified as individual property names or arrays of property names. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Object)*: Returns the new object. #### Example ```js var object = { 'user': 'fred', 'age': 40 }; _.omit(object, 'age'); // => { 'user': 'fred' } _.omit(object, _.isNumber); // => { 'user': 'fred' } ``` * * * ### `_.pairs(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10041 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pairs "See the npm package") Creates a two dimensional array of the key-value pairs for `object`, e.g. `[[key1, value1], [key2, value2]]`. #### Arguments 1. `object` *(Object)*: The object to query. #### Returns *(Array)*: Returns the new array of key-value pairs. #### Example ```js _.pairs({ 'barney': 36, 'fred': 40 }); // => [['barney', 36], ['fred', 40]] (iteration order is not guaranteed) ``` * * * ### `_.pick(object, [predicate], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10082 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pick "See the npm package") Creates an object composed of the picked `object` properties. Property names may be specified as individual arguments or as arrays of property names. If `predicate` is provided it's invoked for each property of `object` picking the properties `predicate` returns truthy for. The predicate is bound to `thisArg` and invoked with three arguments: (value, key, object). #### Arguments 1. `object` *(Object)*: The source object. 2. `[predicate]` *(Function|...(string|string[])*: The function invoked per iteration or property names to pick, specified as individual property names or arrays of property names. 3. `[thisArg]` *(*)*: The `this` binding of `predicate`. #### Returns *(Object)*: Returns the new object. #### Example ```js var object = { 'user': 'fred', 'age': 40 }; _.pick(object, 'user'); // => { 'user': 'fred' } _.pick(object, _.isString); // => { 'user': 'fred' } ``` * * * ### `_.result(object, path, [defaultValue])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10119 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.result "See the npm package") This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned. #### Arguments 1. `object` *(Object)*: The object to query. 2. `path` *(Array|string)*: The path of the property to resolve. 3. `[defaultValue]` *(*)*: The value returned if the resolved value is `undefined`. #### Returns *(*)*: Returns the resolved value. #### Example ```js var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] }; _.result(object, 'a[0].b.c1'); // => 3 _.result(object, 'a[0].b.c2'); // => 4 _.result(object, 'a.b.c', 'default'); // => 'default' _.result(object, 'a.b.c', _.constant('default')); // => 'default' ``` * * * ### `_.set(object, path, value)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10155 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.set "See the npm package") Sets the property value of `path` on `object`. If a portion of `path` does not exist it's created. #### Arguments 1. `object` *(Object)*: The object to augment. 2. `path` *(Array|string)*: The path of the property to set. 3. `value` *(*)*: The value to set. #### Returns *(Object)*: Returns `object`. #### Example ```js var object = { 'a': [{ 'b': { 'c': 3 } }] }; _.set(object, 'a[0].b.c', 4); console.log(object.a[0].b.c); // => 4 _.set(object, 'x[0].y.z', 5); console.log(object.x[0].y.z); // => 5 ``` * * * ### `_.transform(object, [iteratee=_.identity], [accumulator], [thisArg])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10210 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.transform "See the npm package") An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable properties through `iteratee`, with each invocation potentially mutating the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`. #### Arguments 1. `object` *(Array|Object)*: The object to iterate over. 2. `[iteratee=_.identity]` *(Function)*: The function invoked per iteration. 3. `[accumulator]` *(*)*: The custom accumulator value. 4. `[thisArg]` *(*)*: The `this` binding of `iteratee`. #### Returns *(*)*: Returns the accumulated value. #### Example ```js _.transform([2, 3, 4], function(result, n) { result.push(n *= n); return n % 2 == 0; }); // => [4, 9] _.transform({ 'a': 1, 'b': 2 }, function(result, n, key) { result[key] = n * 3; }); // => { 'a': 3, 'b': 6 } ``` * * * ### `_.values(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10257 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.values "See the npm package") Creates an array of the own enumerable property values of `object`.

**Note:** Non-object values are coerced to objects. #### Arguments 1. `object` *(Object)*: The object to query. #### Returns *(Array)*: Returns the array of property values. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.values(new Foo); // => [1, 2] (iteration order is not guaranteed) _.values('hi'); // => ['h', 'i'] ``` * * * ### `_.valuesIn(object)` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10284 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.valuesin "See the npm package") Creates an array of the own and inherited enumerable property values of `object`.

**Note:** Non-object values are coerced to objects. #### Arguments 1. `object` *(Object)*: The object to query. #### Returns *(Array)*: Returns the array of property values. #### Example ```js function Foo() { this.a = 1; this.b = 2; } Foo.prototype.c = 3; _.valuesIn(new Foo); // => [1, 2, 3] (iteration order is not guaranteed) ``` * * * ## `“String” Methods` ### `_.camelCase([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10415 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.camelcase "See the npm package") Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase). #### Arguments 1. `[string='']` *(string)*: The string to convert. #### Returns *(string)*: Returns the camel cased string. #### Example ```js _.camelCase('Foo Bar'); // => 'fooBar' _.camelCase('--foo-bar'); // => 'fooBar' _.camelCase('__foo_bar__'); // => 'fooBar' ``` * * * ### `_.capitalize([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10433 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.capitalize "See the npm package") Capitalizes the first character of `string`. #### Arguments 1. `[string='']` *(string)*: The string to capitalize. #### Returns *(string)*: Returns the capitalized string. #### Example ```js _.capitalize('fred'); // => 'Fred' ``` * * * ### `_.deburr([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10452 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.deburr "See the npm package") Deburrs `string` by converting [latin-1 supplementary letters](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) to basic latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). #### Arguments 1. `[string='']` *(string)*: The string to deburr. #### Returns *(string)*: Returns the deburred string. #### Example ```js _.deburr('déjà vu'); // => 'deja vu' ``` * * * ### `_.endsWith([string=''], [target], [position=string.length])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10478 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.endswith "See the npm package") Checks if `string` ends with the given target string. #### Arguments 1. `[string='']` *(string)*: The string to search. 2. `[target]` *(string)*: The string to search for. 3. `[position=string.length]` *(number)*: The position to search from. #### Returns *(boolean)*: Returns `true` if `string` ends with `target`, else `false`. #### Example ```js _.endsWith('abc', 'c'); // => true _.endsWith('abc', 'b'); // => false _.endsWith('abc', 'b', 2); // => true ``` * * * ### `_.escape([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10523 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.escape "See the npm package") Converts the characters "&", "<", ">", '"', "'", and "\`", in `string` to their corresponding HTML entities.

**Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he).

Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details.

Backticks are escaped because in Internet Explorer < 9, they can break out of attribute values or HTML comments. See [#59](https://html5sec.org/#59), [#102](https://html5sec.org/#102), [#108](https://html5sec.org/#108), and [#133](https://html5sec.org/#133) of the [HTML5 Security Cheatsheet](https://html5sec.org/) for more details.

When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors. #### Arguments 1. `[string='']` *(string)*: The string to escape. #### Returns *(string)*: Returns the escaped string. #### Example ```js _.escape('fred, barney, & pebbles'); // => 'fred, barney, & pebbles' ``` * * * ### `_.escapeRegExp([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10545 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.escaperegexp "See the npm package") Escapes the `RegExp` special characters "\", "/", "^", "$", ".", "|", "?", "*", "+", "(", ")", "[", "]", "{" and "}" in `string`. #### Arguments 1. `[string='']` *(string)*: The string to escape. #### Returns *(string)*: Returns the escaped string. #### Example ```js _.escapeRegExp('[lodash](https://lodash.com/)'); // => '\[lodash\]\(https:\/\/lodash\.com\/\)' ``` * * * ### `_.kebabCase([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10571 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.kebabcase "See the npm package") Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles). #### Arguments 1. `[string='']` *(string)*: The string to convert. #### Returns *(string)*: Returns the kebab cased string. #### Example ```js _.kebabCase('Foo Bar'); // => 'foo-bar' _.kebabCase('fooBar'); // => 'foo-bar' _.kebabCase('__foo_bar__'); // => 'foo-bar' ``` * * * ### `_.pad([string=''], [length=0], [chars=' '])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10597 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.pad "See the npm package") Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`. #### Arguments 1. `[string='']` *(string)*: The string to pad. 2. `[length=0]` *(number)*: The padding length. 3. `[chars=' ']` *(string)*: The string used as padding. #### Returns *(string)*: Returns the padded string. #### Example ```js _.pad('abc', 8); // => ' abc ' _.pad('abc', 8, '_-'); // => '_-abc_-_' _.pad('abc', 3); // => 'abc' ``` * * * ### `_.padLeft([string=''], [length=0], [chars=' '])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10635 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.padleft "See the npm package") Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`. #### Arguments 1. `[string='']` *(string)*: The string to pad. 2. `[length=0]` *(number)*: The padding length. 3. `[chars=' ']` *(string)*: The string used as padding. #### Returns *(string)*: Returns the padded string. #### Example ```js _.padLeft('abc', 6); // => ' abc' _.padLeft('abc', 6, '_-'); // => '_-_abc' _.padLeft('abc', 3); // => 'abc' ``` * * * ### `_.padRight([string=''], [length=0], [chars=' '])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10659 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.padright "See the npm package") Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`. #### Arguments 1. `[string='']` *(string)*: The string to pad. 2. `[length=0]` *(number)*: The padding length. 3. `[chars=' ']` *(string)*: The string used as padding. #### Returns *(string)*: Returns the padded string. #### Example ```js _.padRight('abc', 6); // => 'abc ' _.padRight('abc', 6, '_-'); // => 'abc_-_' _.padRight('abc', 3); // => 'abc' ``` * * * ### `_.parseInt(string, [radix])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10684 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.parseint "See the npm package") Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used.

**Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#E) of `parseInt`. #### Arguments 1. `string` *(string)*: The string to convert. 2. `[radix]` *(number)*: The radix to interpret `value` by. #### Returns *(number)*: Returns the converted integer. #### Example ```js _.parseInt('08'); // => 8 _.map(['6', '08', '10'], _.parseInt); // => [6, 8, 10] ``` * * * ### `_.repeat([string=''], [n=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10717 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.repeat "See the npm package") Repeats the given string `n` times. #### Arguments 1. `[string='']` *(string)*: The string to repeat. 2. `[n=0]` *(number)*: The number of times to repeat the string. #### Returns *(string)*: Returns the repeated string. #### Example ```js _.repeat('*', 3); // => '***' _.repeat('abc', 2); // => 'abcabc' _.repeat('abc', 0); // => '' ``` * * * ### `_.snakeCase([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10756 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.snakecase "See the npm package") Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case). #### Arguments 1. `[string='']` *(string)*: The string to convert. #### Returns *(string)*: Returns the snake cased string. #### Example ```js _.snakeCase('Foo Bar'); // => 'foo_bar' _.snakeCase('fooBar'); // => 'foo_bar' _.snakeCase('--foo-bar'); // => 'foo_bar' ``` * * * ### `_.startCase([string=''])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10779 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.startcase "See the npm package") Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage). #### Arguments 1. `[string='']` *(string)*: The string to convert. #### Returns *(string)*: Returns the start cased string. #### Example ```js _.startCase('--foo-bar'); // => 'Foo Bar' _.startCase('fooBar'); // => 'Foo Bar' _.startCase('__foo_bar__'); // => 'Foo Bar' ``` * * * ### `_.startsWith([string=''], [target], [position=0])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10804 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.startswith "See the npm package") Checks if `string` starts with the given target string. #### Arguments 1. `[string='']` *(string)*: The string to search. 2. `[target]` *(string)*: The string to search for. 3. `[position=0]` *(number)*: The position to search from. #### Returns *(boolean)*: Returns `true` if `string` starts with `target`, else `false`. #### Example ```js _.startsWith('abc', 'a'); // => true _.startsWith('abc', 'b'); // => false _.startsWith('abc', 'b', 1); // => true ``` * * * ### `_.template([string=''], [options])` # [Ⓢ](https://github.com/lodash/lodash/blob/3.10.1/lodash.src.js#L10909 "View in source") [Ⓣ][1] [Ⓝ](https://www.npmjs.com/package/lodash.template "See the npm package") Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is provided it takes precedence over `_.templateSettings` values.

**Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging.

For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds).

For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval). #### Arguments 1. `[string='']` *(string)*: The template string. 2. `[options]` *(Object)*: The options object. 3. `[options.escape]` *(RegExp)*: The HTML "escape" delimiter. 4. `[options.evaluate]` *(RegExp)*: The "evaluate" delimiter. 5. `[options.imports]` *(Object)*: An object to import into the template as free variables. 6. `[options.interpolate]` *(RegExp)*: The "interpolate" delimiter. 7. `[options.sourceURL]` *(string)*: The sourceURL of the template's compiled source. 8. `[options.variable]` *(string)*: The data object variable name. #### Returns *(Function)*: Returns the compiled template function. #### Example ```js // using the "interpolate" delimiter to create a compiled template var compiled = _.template('hello <%= user %>!'); compiled({ 'user': 'fred' }); // => 'hello fred!' // using the HTML "escape" delimiter to escape data property values var compiled = _.template('<%- value %>'); compiled({ 'value': '