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WeakSet() - JavaScript | MDN
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WeakSet()

Baseline Widely available

This feature is well established and works across many devices and browser versions. Its been available across browsers since 2015 9.

WeakSet() WeakSet .

In this article

js
new WeakSet()
new WeakSet(iterable)

: WeakSet() new . new TypeError .

iterable Optional

, WeakSet . null undefined .

WeakSet

js
const ws = new WeakSet();
const foo = {};
const bar = {};

ws.add(foo);
ws.add(bar);

ws.has(foo); // true
ws.has(bar); // true

ws.delete(foo); // foo  set 
ws.has(foo); // false, foo  
ws.has(bar); // true, bar

foo !== bar . . set .

Specification
ECMAScript 2027 LanguageSpecification
# sec-weakset-constructor

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