object/pick.js

define(['../internal/baseFlatten', '../internal/bindCallback', '../internal/pickByArray', '../internal/pickByCallback'], function(baseFlatten, bindCallback, pickByArray, pickByCallback) {

  /**
   * Creates an object composed of the picked `object` properties. Property
   * names may be specified as individual arguments or as arrays of property
   * names. If `predicate` is provided it is invoked for each property of `object`
   * picking the properties `predicate` returns truthy for. The predicate is
   * bound to `thisArg` and invoked with three arguments; (value, key, object).
   *
   * @static
   * @memberOf _
   * @category Object
   * @param {Object} object The source object.
   * @param {Function|...(string|string[])} [predicate] The function invoked per
   *  iteration or property names to pick, specified as individual property
   *  names or arrays of property names.
   * @param {*} [thisArg] The `this` binding of `predicate`.
   * @returns {Object} Returns the new object.
   * @example
   *
   * var object = { 'user': 'fred', 'age': 40 };
   *
   * _.pick(object, 'user');
   * // => { 'user': 'fred' }
   *
   * _.pick(object, _.isString);
   * // => { 'user': 'fred' }
   */
  function pick(object, predicate, thisArg) {
    if (object == null) {
      return {};
    }
    return typeof predicate == 'function'
      ? pickByCallback(object, bindCallback(predicate, thisArg, 3))
      : pickByArray(object, baseFlatten(arguments, false, false, 1));
  }

  return pick;
});