| var baseFindIndex = require('./_baseFindIndex'), | |
| baseIteratee = require('./_baseIteratee'), | |
| toInteger = require('./toInteger'); | |
| /* Built-in method references for those with the same name as other `lodash` methods. */ | |
| var nativeMax = Math.max; | |
| /** | |
| * This method is like `_.find` except that it returns the index of the first | |
| * element `predicate` returns truthy for instead of the element itself. | |
| * | |
| * @static | |
| * @memberOf _ | |
| * @since 1.1.0 | |
| * @category Array | |
| * @param {Array} array The array to inspect. | |
| * @param {Function} [predicate=_.identity] The function invoked per iteration. | |
| * @param {number} [fromIndex=0] The index to search from. | |
| * @returns {number} Returns the index of the found element, else `-1`. | |
| * @example | |
| * | |
| * var users = [ | |
| * { 'user': 'barney', 'active': false }, | |
| * { 'user': 'fred', 'active': false }, | |
| * { 'user': 'pebbles', 'active': true } | |
| * ]; | |
| * | |
| * _.findIndex(users, function(o) { return o.user == 'barney'; }); | |
| * // => 0 | |
| * | |
| * // The `_.matches` iteratee shorthand. | |
| * _.findIndex(users, { 'user': 'fred', 'active': false }); | |
| * // => 1 | |
| * | |
| * // The `_.matchesProperty` iteratee shorthand. | |
| * _.findIndex(users, ['active', false]); | |
| * // => 0 | |
| * | |
| * // The `_.property` iteratee shorthand. | |
| * _.findIndex(users, 'active'); | |
| * // => 2 | |
| */ | |
| function findIndex(array, predicate, fromIndex) { | |
| var length = array == null ? 0 : array.length; | |
| if (!length) { | |
| return -1; | |
| } | |
| var index = fromIndex == null ? 0 : toInteger(fromIndex); | |
| if (index < 0) { | |
| index = nativeMax(length + index, 0); | |
| } | |
| return baseFindIndex(array, baseIteratee(predicate, 3), index); | |
| } | |
| module.exports = findIndex; |