map.js (1621B)
1 var arrayMap = require('./_arrayMap'), 2 baseIteratee = require('./_baseIteratee'), 3 baseMap = require('./_baseMap'), 4 isArray = require('./isArray'); 5 6 /** 7 * Creates an array of values by running each element in `collection` thru 8 * `iteratee`. The iteratee is invoked with three arguments: 9 * (value, index|key, collection). 10 * 11 * Many lodash methods are guarded to work as iteratees for methods like 12 * `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. 13 * 14 * The guarded methods are: 15 * `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, 16 * `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, 17 * `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, 18 * `template`, `trim`, `trimEnd`, `trimStart`, and `words` 19 * 20 * @static 21 * @memberOf _ 22 * @since 0.1.0 23 * @category Collection 24 * @param {Array|Object} collection The collection to iterate over. 25 * @param {Function} [iteratee=_.identity] The function invoked per iteration. 26 * @returns {Array} Returns the new mapped array. 27 * @example 28 * 29 * function square(n) { 30 * return n * n; 31 * } 32 * 33 * _.map([4, 8], square); 34 * // => [16, 64] 35 * 36 * _.map({ 'a': 4, 'b': 8 }, square); 37 * // => [16, 64] (iteration order is not guaranteed) 38 * 39 * var users = [ 40 * { 'user': 'barney' }, 41 * { 'user': 'fred' } 42 * ]; 43 * 44 * // The `_.property` iteratee shorthand. 45 * _.map(users, 'user'); 46 * // => ['barney', 'fred'] 47 */ 48 function map(collection, iteratee) { 49 var func = isArray(collection) ? arrayMap : baseMap; 50 return func(collection, baseIteratee(iteratee, 3)); 51 } 52 53 module.exports = map;