123456789101112131415161718192021 |
- 'use strict';
- var wellKnownSymbol = require('../internals/well-known-symbol');
- var create = require('../internals/object-create');
- var defineProperty = require('../internals/object-define-property').f;
-
- var UNSCOPABLES = wellKnownSymbol('unscopables');
- var ArrayPrototype = Array.prototype;
-
- // Array.prototype[@@unscopables]
- // https://tc39.es/ecma262/#sec-array.prototype-@@unscopables
- if (ArrayPrototype[UNSCOPABLES] === undefined) {
- defineProperty(ArrayPrototype, UNSCOPABLES, {
- configurable: true,
- value: create(null)
- });
- }
-
- // add a key to Array.prototype[@@unscopables]
- module.exports = function (key) {
- ArrayPrototype[UNSCOPABLES][key] = true;
- };
|