invertBy.js (1343B)
1 var baseIteratee = require('./_baseIteratee'), 2 createInverter = require('./_createInverter'); 3 4 /** Used for built-in method references. */ 5 var objectProto = Object.prototype; 6 7 /** Used to check objects for own properties. */ 8 var hasOwnProperty = objectProto.hasOwnProperty; 9 10 /** 11 * This method is like `_.invert` except that the inverted object is generated 12 * from the results of running each element of `object` thru `iteratee`. The 13 * corresponding inverted value of each inverted key is an array of keys 14 * responsible for generating the inverted value. The iteratee is invoked 15 * with one argument: (value). 16 * 17 * @static 18 * @memberOf _ 19 * @since 4.1.0 20 * @category Object 21 * @param {Object} object The object to invert. 22 * @param {Function} [iteratee=_.identity] The iteratee invoked per element. 23 * @returns {Object} Returns the new inverted object. 24 * @example 25 * 26 * var object = { 'a': 1, 'b': 2, 'c': 1 }; 27 * 28 * _.invertBy(object); 29 * // => { '1': ['a', 'c'], '2': ['b'] } 30 * 31 * _.invertBy(object, function(value) { 32 * return 'group' + value; 33 * }); 34 * // => { 'group1': ['a', 'c'], 'group2': ['b'] } 35 */ 36 var invertBy = createInverter(function(result, value, key) { 37 if (hasOwnProperty.call(result, value)) { 38 result[value].push(key); 39 } else { 40 result[value] = [key]; 41 } 42 }, baseIteratee); 43 44 module.exports = invertBy;