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JavaScript WeakSet Reference

Last Updated : 23 Jul, 2025

JavaScript WeakSet is used to store a collection of objects. It adapts the same properties as that of a set i.e. does not store duplicates. The major difference between WeakSet and a set is that a WeakSet is a collection of objects and not values of some particular type.

Syntax:

weakSet.function();

Example: In this example, we will use the JavaScript weakSet() method.

JavaScript
// Constructing a weakSet() object
const A = new WeakSet();

// Constructing new objects
const object1 = {};

// Adding the new object to the weakSet
A.add(object1);

// Checking whether the new object is present
// in the weakSet or not
console.log(A.has(object1));

Output
true

The complete list of JavaScript WeakSet is listed below:

JavaScript WeakSet Constructor: In JavaScript, a constructor gets called when an object is created using the new keyword.

ConstructorDescription
weakSet()A constructor gets called when an object is created using the new keyword.

JavaScript WeakSet Properties: A JavaScript property is a member of an object that associates a key with a value. There is no static property in the weakSet only instance property.

  • Instance Properties: An instance property is a property that has a new copy for every new instance of the class.
Instance PropertyDescription
constructorReturn the wekaMap constructor function for the object.

JavaScript WeakSet Method: JavaScript methods are actions that can be performed on objects.

  • Instance Method: If the method is called on an instance of a WeakSet then it is called an instance method of WeakSet.
Instance MethodDescription
add()Add an object at the end of an object WeakSet.
delete()Delete a specific element from a weakSet object.
has()Return a boolean value indicating whether an object is present in a weakSet or not. that
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