findLastIndex.js (1761B)
1 var baseFindIndex = require('./_baseFindIndex'), 2 baseIteratee = require('./_baseIteratee'), 3 toInteger = require('./toInteger'); 4 5 /* Built-in method references for those with the same name as other `lodash` methods. */ 6 var nativeMax = Math.max, 7 nativeMin = Math.min; 8 9 /** 10 * This method is like `_.findIndex` except that it iterates over elements 11 * of `collection` from right to left. 12 * 13 * @static 14 * @memberOf _ 15 * @since 2.0.0 16 * @category Array 17 * @param {Array} array The array to inspect. 18 * @param {Function} [predicate=_.identity] The function invoked per iteration. 19 * @param {number} [fromIndex=array.length-1] The index to search from. 20 * @returns {number} Returns the index of the found element, else `-1`. 21 * @example 22 * 23 * var users = [ 24 * { 'user': 'barney', 'active': true }, 25 * { 'user': 'fred', 'active': false }, 26 * { 'user': 'pebbles', 'active': false } 27 * ]; 28 * 29 * _.findLastIndex(users, function(o) { return o.user == 'pebbles'; }); 30 * // => 2 31 * 32 * // The `_.matches` iteratee shorthand. 33 * _.findLastIndex(users, { 'user': 'barney', 'active': true }); 34 * // => 0 35 * 36 * // The `_.matchesProperty` iteratee shorthand. 37 * _.findLastIndex(users, ['active', false]); 38 * // => 2 39 * 40 * // The `_.property` iteratee shorthand. 41 * _.findLastIndex(users, 'active'); 42 * // => 0 43 */ 44 function findLastIndex(array, predicate, fromIndex) { 45 var length = array == null ? 0 : array.length; 46 if (!length) { 47 return -1; 48 } 49 var index = length - 1; 50 if (fromIndex !== undefined) { 51 index = toInteger(fromIndex); 52 index = fromIndex < 0 53 ? nativeMax(length + index, 0) 54 : nativeMin(index, length - 1); 55 } 56 return baseFindIndex(array, baseIteratee(predicate, 3), index, true); 57 } 58 59 module.exports = findLastIndex;