lodash/collection/invoke.js

define(['../internal/baseEach', '../internal/getLength', '../internal/invokePath', '../internal/isKey', '../internal/isLength', '../function/restParam'], function(baseEach, getLength, invokePath, isKey, isLength, restParam) {

  /**
   * Invokes the method at `path` on each element in `collection`, returning
   * an array of the results of each invoked method. Any additional arguments
   * are provided to each invoked method. If `methodName` is a function it is
   * invoked for, and `this` bound to, each element in `collection`.
   *
   * @static
   * @memberOf _
   * @category Collection
   * @param {Array|Object|string} collection The collection to iterate over.
   * @param {Array|Function|string} path The path of the method to invoke or
   *  the function invoked per iteration.
   * @param {...*} [args] The arguments to invoke the method with.
   * @returns {Array} Returns the array of results.
   * @example
   *
   * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
   * // => [[1, 5, 7], [1, 2, 3]]
   *
   * _.invoke([123, 456], String.prototype.split, '');
   * // => [['1', '2', '3'], ['4', '5', '6']]
   */
  var invoke = restParam(function(collection, path, args) {
    var index = -1,
        isFunc = typeof path == 'function',
        isProp = isKey(path),
        length = getLength(collection),
        result = isLength(length) ? Array(length) : [];

    baseEach(collection, function(value) {
      var func = isFunc ? path : (isProp && value != null && value[path]);
      result[++index] = func ? func.apply(value, args) : invokePath(value, path, args);
    });
    return result;
  });

  return invoke;
});