| 'use strict'; |
| var DESCRIPTORS = require('../internals/descriptors'); |
| var addToUnscopables = require('../internals/add-to-unscopables'); |
| var toObject = require('../internals/to-object'); |
| var toLength = require('../internals/to-length'); |
| var defineProperty = require('../internals/object-define-property').f; |
| |
| // `Array.prototype.lastIndex` getter |
| // https://github.com/keithamus/proposal-array-last |
| if (DESCRIPTORS && !('lastIndex' in [])) { |
| defineProperty(Array.prototype, 'lastIndex', { |
| configurable: true, |
| get: function lastIndex() { |
| var O = toObject(this); |
| var len = toLength(O.length); |
| return len == 0 ? 0 : len - 1; |
| } |
| }); |
| |
| addToUnscopables('lastIndex'); |
| } |