The get() method of WeakMap instances returns a specified element from this WeakMap.
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WeakMap.prototype.get()
Try it
Syntax
js
get(key)
Parameters
-
key -
The key of the element to return from the
WeakMapobject.
Return value
The element associated with the specified key in the WeakMap object. If the key can't be found, undefined is returned. Always returns undefined if key is not an object or a non-registered symbol.
Examples
Using the get() method
js
const wm = new WeakMap();
wm.set(window, "foo");
wm.get(window); // Returns "foo".
wm.get("baz"); // Returns undefined.
Specifications
Browser compatibility
| Desktop | Mobile | Server | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
get |
36 | 12 |
6Before Firefox 38, this method threw aTypeError 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.
|
23 | 8 | 36 |
6Before Firefox 38, this method threw aTypeError 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.
|
24 | 8 | 3.0 | 37 | 1.0 | 0.12.0 | |
See also
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/get