The has()
method returns a boolean indicating whether an object exists in a WeakSet
or not.
ws.has(value);
WeakSet
.true
if an element with the specified value exists in the WeakSet
object; otherwise false
.has
methodvar ws = new WeakSet(); var obj = {}; ws.add(window); mySet.has(window); // returns true mySet.has(obj); // returns false
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'WeakSet.prototype.has' in that specification. | Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'WeakSet.prototype.has' in that specification. | Draft |
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 36 | Yes | 34 | No | 23 | 9 |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
---|---|---|---|---|---|---|---|
Basic support | 36 | 36 | Yes | 34 | 23 | 9 | ? |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet/has