Split _.fromPairs into _.zipObject.

lodash.js

@@ -1508,7 +1508,8 @@
      * `thru`, `toArray`, `toPairs`, `toPairsIn`, `toPath`, `toPlainObject`,
      * `transform`, `unary`, `union`, `unionBy`, `unionWith`, `uniq`, `uniqBy`,
      * `uniqWith`, `unset`, `unshift`, `unzip`, `unzipWith`, `values`, `valuesIn`,
-     * `without`, `wrap`, `xor`, `xorBy`, `xorWith`, `zip`, and `zipWith`
+     * `without`, `wrap`, `xor`, `xorBy`, `xorWith`, `zip`, `zipObject`,
+     * and `zipWith`
      *
      * The wrapper methods that are **not** chainable by default are:
      * `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clamp`, `clone`,
@@ -5611,40 +5612,27 @@
     }
 
     /**
-     * The inverse of `_.toPairs`; 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.
+     * The inverse of `_.toPairs`; this method returns an object composed
+     * from key-value `pairs`.
      *
      * @static
      * @memberOf _
      * @category Array
-     * @param {Array} props The property names.
-     * @param {Array} [values=[]] The property values.
+     * @param {Array} pairs The key-value pairs.
      * @returns {Object} Returns the new object.
      * @example
      *
      * _.fromPairs([['fred', 30], ['barney', 40]]);
      * // => { 'fred': 30, 'barney': 40 }
-     *
-     * _.fromPairs(['fred', 'barney'], [30, 40]);
-     * // => { 'fred': 30, 'barney': 40 }
      */
-    function fromPairs(props, values) {
+    function fromPairs(pairs) {
       var index = -1,
-          length = props ? props.length : 0,
+          length = pairs ? pairs.length : 0,
           result = {};
 
-      if (length && !values && !isArray(props[0])) {
-        values = [];
-      }
       while (++index < length) {
-        var key = props[index];
-        if (values) {
-          baseSet(result, key, values[index]);
-        } else if (key) {
-          baseSet(result, key[0], key[1]);
-        }
+        var pair = pairs[index];
+        baseSet(result, pair[0], pair[1]);
       }
       return result;
     }
@@ -6770,6 +6758,33 @@
      */
     var zip = rest(unzip);
 
+    /**
+     * This method is like `_.fromPairs` except that it accepts two arrays,
+     * one of property names and one of corresponding values.
+     *
+     * @static
+     * @memberOf _
+     * @category Array
+     * @param {Array} [props=[]] The property names.
+     * @param {Array} [values=[]] The property values.
+     * @returns {Object} Returns the new object.
+     * @example
+     *
+     * _.zipObject(['fred', 'barney'], [30, 40]);
+     * // => { 'fred': 30, 'barney': 40 }
+     */
+    function zipObject(props, values) {
+      var index = -1,
+          length = props ? props.length : 0,
+          valsLength = values ? values.length : 0,
+          result = {};
+
+      while (++index < length) {
+        baseSet(result, props[index], index < valsLength ? values[index] : undefined);
+      }
+      return result;
+    }
+
     /**
      * This method is like `_.zip` except that it accepts `iteratee` to specify
      * how grouped values should be combined. The iteratee is invoked with four
@@ -13775,6 +13790,7 @@
     lodash.xorBy = xorBy;
     lodash.xorWith = xorWith;
     lodash.zip = zip;
+    lodash.zipObject = zipObject;
     lodash.zipWith = zipWith;
 
     // Add aliases.