The get()
method returns a specified element from a WeakMap
object.
Syntax
wm.get(key);
Parameters
- key
- Required. The key of the element to return from the
WeakMap
object.
Return value
The element associated with the specified key in the WeakMap
object. If the key can't be found, undefined
is returned.
Examples
Using the get
method
var wm = new WeakMap(); wm.set(window, 'foo'); wm.get(window); // Returns "foo". wm.get('baz'); // Returns undefined.
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'WeakMap.prototype.get' in that specification. |
Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'WeakMap.prototype.get' 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 | 61 | 11 | 23 | 8 |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | 36 | 36 | Yes | 61 | 11 | 23 | 8 |
1. Prior to Firefox 38, this method threw a TypeError
when the key parameter was not an object. However, the ES2015 specification specifies to return undefined
instead. Furthermore, WeakMap.prototype.get
accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher.