WeakSet.prototype.has()

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

Syntax

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
ECMAScript Language Specification (ECMAScript)
# sec-weakset.prototype.has

Browser compatibility

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See also