1 | /* tslint:disable */
|
2 | /* eslint-disable no-extend-native */
|
3 | // https://tc39.github.io/ecma262/#sec-array.prototype.includes
|
4 | if (!Array.prototype.includes) {
|
5 | Object.defineProperty(Array.prototype, 'includes', {
|
6 | configurable: true,
|
7 | value: function (searchElement, fromIndex) {
|
8 |
|
9 | if (this == null) {
|
10 | throw new TypeError('"this" is null or not defined');
|
11 | }
|
12 |
|
13 | // 1. Let O be ? ToObject(this value).
|
14 | var o = Object(this);
|
15 |
|
16 | // 2. Let len be ? ToLength(? Get(O, "length")).
|
17 | var len = o.length >>> 0;
|
18 |
|
19 | // 3. If len is 0, return false.
|
20 | if (len === 0) {
|
21 | return false;
|
22 | }
|
23 |
|
24 | // 4. Let n be ? ToInteger(fromIndex).
|
25 | // (If fromIndex is undefined, this step produces the value 0.)
|
26 | var n = fromIndex | 0;
|
27 |
|
28 | // 5. If n ≥ 0, then
|
29 | // a. Let k be n.
|
30 | // 6. Else n < 0,
|
31 | // a. Let k be len + n.
|
32 | // b. If k < 0, let k be 0.
|
33 | var k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
|
34 |
|
35 | function sameValueZero(x, y) {
|
36 | return x === y || (typeof x === 'number' && typeof y === 'number' && isNaN(x) && isNaN(y));
|
37 | }
|
38 |
|
39 | // 7. Repeat, while k < len
|
40 | while (k < len) {
|
41 | // a. Let elementK be the result of ? Get(O, ! ToString(k)).
|
42 | // b. If SameValueZero(searchElement, elementK) is true, return true.
|
43 | if (sameValueZero(o[k], searchElement)) {
|
44 | return true;
|
45 | }
|
46 | // c. Increase k by 1.
|
47 | k++;
|
48 | }
|
49 |
|
50 | // 8. Return false
|
51 | return false;
|
52 | }
|
53 | });
|
54 | } |
\ | No newline at end of file |