var arrayMap = require('../internal/arrayMap'), baseCallback = require('../internal/baseCallback'), baseMap = require('../internal/baseMap'), isArray = require('../lang/isArray'); /** * Creates an array of values by running each element in `collection` through * `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three * arguments; (value, index|key, collection). * * If a property name is provided for `predicate` the created "_.property" * style callback returns the property value of the given element. * * If value is also provided for `thisArg` the created "_.matchesProperty" * style callback returns `true` for elements that have a matching property * value, else `false`. * * If an object is provided for `predicate` the created "_.matches" style * callback returns `true` for elements that have the properties of the given * object, else `false`. * * Many lodash methods are guarded to work as interatees for methods like * `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. * * The guarded methods are: * `ary`, `callback`, `chunk`, `clone`, `create`, `curry`, `curryRight`, `drop`, * `dropRight`, `fill`, `flatten`, `invert`, `max`, `min`, `parseInt`, `slice`, * `sortBy`, `take`, `takeRight`, `template`, `trim`, `trimLeft`, `trimRight`, * `trunc`, `random`, `range`, `sample`, `uniq`, and `words` * * @static * @memberOf _ * @alias collect * @category Collection * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [iteratee=_.identity] The function invoked * per iteration. If a property name or object is provided it is used to * create a "_.property" or "_.matches" style callback respectively. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Array} Returns the new mapped array. * @example * * _.map([1, 2, 3], function(n) { return n * 3; }); * // => [3, 6, 9] * * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(n) { return n * 3; }); * // => [3, 6, 9] (iteration order is not guaranteed) * * var users = [ * { 'user': 'barney' }, * { 'user': 'fred' } * ]; * * // using the "_.property" callback shorthand * _.map(users, 'user'); * // => ['barney', 'fred'] */ function map(collection, iteratee, thisArg) { var func = isArray(collection) ? arrayMap : baseMap; iteratee = baseCallback(iteratee, thisArg, 3); return func(collection, iteratee); } module.exports = map;