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weakSet.has

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

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
has 36 12 34 No 23 9
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
has 37 36 34 24 9 3.0
Server
Node.js
has 0.12

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet/has