The has() method returns a boolean indicating whether an object exists in a WeakSet or not.

Syntax

ws.has(value);

Parameters

value
Required. The object to test for presence in the WeakSet.

Return value

Boolean
Returns true if an element with the specified value exists in the WeakSet object; otherwise false.

Examples

Using the has method

var ws = new WeakSet();
var obj = {};
ws.add(window);

mySet.has(window);  // returns true
mySet.has(obj);     // returns false

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'WeakSet.prototype.has' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'WeakSet.prototype.has' in that specification.
Draft  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support36 Yes34 No239
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support3636 Yes34239 Yes

See also

Document Tags and Contributors

Contributors to this page: wbamberg, fscholz, jameshkramer, kdex, realityking, teoli
Last updated by: wbamberg,