2 var DESCRIPTORS = require('../internals/descriptors');
3 var addToUnscopables = require('../internals/add-to-unscopables');
4 var toObject = require('../internals/to-object');
5 var toLength = require('../internals/to-length');
6 var defineProperty = require('../internals/object-define-property').f;
8 // `Array.prototype.lastIndex` accessor
9 // https://github.com/keithamus/proposal-array-last
10 if (DESCRIPTORS && !('lastItem' in [])) {
11 defineProperty(Array.prototype, 'lastItem', {
13 get: function lastItem() {
14 var O = toObject(this);
15 var len = toLength(O.length);
16 return len == 0 ? undefined : O[len - 1];
18 set: function lastItem(value) {
19 var O = toObject(this);
20 var len = toLength(O.length);
21 return O[len == 0 ? 0 : len - 1] = value;
25 addToUnscopables('lastItem');