WeakMap.prototype.get()

The get() method returns a specified element from a WeakMap object.

Syntax

get(key)

key: Required. 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.

var wm = new WeakMap();
wm.set(window, 'foo');

wm.get(window); // Returns "foo".
wm.get('baz');  // Returns undefined.

Specification
ECMAScript Language Specification (ECMAScript) # sec-weakmap.prototype.get

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`get`	36	12	6 Before 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.	11	23	8	37	36	6 Before 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.	24	8	3.0