The get()
method of WeakMap
instances returns a specified element from this WeakMap
.
The get()
method of WeakMap
instances returns a specified element from this WeakMap
.
get(key)
key
The key of the element to return from the WeakMap
object.
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.
const wm = new WeakMap(); wm.set(window, "foo"); wm.get(window); // Returns "foo". wm.get("baz"); // Returns undefined.
Desktop | Mobile | Server | ||||||||||||
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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 |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/get