The add()
method appends a new object to the end of a WeakSet
object.
Syntax
ws.add(value);
Parameters
- value
- Required. The object to add to the
WeakSet
collection.
Return value
The WeakSet
object.
Using the add
method
var ws = new WeakSet(); ws.add(window); // add the window object to the WeakSet ws.has(window); // true // Weakset only takes objects as arguments ws.add(1); // results in "TypeError: Invalid value used in weak set" in Chrome // and "TypeError: 1 is not a non-null object" in Firefox
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'WeakSet.prototype.add' in that specification. |
Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'WeakSet.prototype.add' in that specification. |
Living Standard |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
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 | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | 36 | 36 | Yes | 34 | No | 23 | 9 |
See also
Document Tags and Contributors
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Contributors to this page:
fscholz,
jameshkramer,
kdex,
eduardoboucas,
chrisdavidmills,
andradei,
realityking,
teoli
Last updated by:
fscholz,