Files
lodash/internal/isIndex.js
2015-02-04 00:42:01 -08:00

23 lines
698 B
JavaScript

/**
* Used as the maximum length of an array-like value.
* See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
* for more details.
*/
var MAX_SAFE_INTEGER = Math.pow(2, 53) - 1;
/**
* Checks if `value` is a valid array-like index.
*
* @private
* @param {*} value The value to check.
* @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
* @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
*/
function isIndex(value, length) {
value = +value;
length = length == null ? MAX_SAFE_INTEGER : length;
return value > -1 && value % 1 == 0 && value < length;
}
module.exports = isIndex;