var createAggregator = require('./_createAggregator'); /** Used for built-in method references. */ var objectProto = Object.prototype; /** Used to check objects for own properties. */ var hasOwnProperty = objectProto.hasOwnProperty; /** * Creates an object composed of keys generated from the results of running * each element of `collection` thru `iteratee`. The order of grouped values * is determined by the order they occur in `collection`. The corresponding * value of each key is an array of elements responsible for generating the * key. The iteratee is invoked with one argument: (value). * * @static * @memberOf _ * @since 0.1.0 * @category Collection * @param {Array|Object} collection The collection to iterate over. * @param {Function} [iteratee=_.identity] * The iteratee to transform keys. * @returns {Object} Returns the composed aggregate object. * @example * * _.groupBy([6.1, 4.2, 6.3], Math.floor); * // => { '4': [4.2], '6': [6.1, 6.3] } * * // The `_.property` iteratee shorthand. * _.groupBy(['one', 'two', 'three'], 'length'); * // => { '3': ['one', 'two'], '5': ['three'] } */ var groupBy = createAggregator(function(result, value, key) { if (hasOwnProperty.call(result, key)) { result[key].push(value); } else { result[key] = [value]; } }); module.exports = groupBy;