JavaScript WeakSet

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

Syntax:

new WeakSet(object)

Parameters: Here parameter “object” is an iterable object. All the elements of the iterable object are added to the WeakSet. 

Return type: It returns a weakset object.

Example 1: In this example, we will create a weakSet object and add an element to it, then we will check if the element exists in the weakSet. We will use has() method and add() method

javascript

function gfg() {
    let weakSetObject = new WeakSet();
    let objectOne = {};

    // add(value)
    weakSetObject.add(objectOne);
    console.log("objectOne added");

    // has(value)
    console.log("WeakSet has objectOne : " +
                    weakSetObject.has(objectOne));
}
gfg();

Output:

objectOne added
true

Example 2: In this example, we will see the working of weakSet functions also we will delete data using the delete() method.

javascript

let weakSetObject = new WeakSet();
let objectOne = {};
let objectTwo = {};

// add(value)
weakSetObject.add(objectOne);
console.log("objectOne added");
weakSetObject.add(objectTwo);
console.log("objectTwo added");

// has(value)
console.log("WeakSet has objectTwo : " +
weakSetObject.has(objectTwo));

// delete(value)
weakSetObject.delete(objectTwo);
console.log("objectTwo deleted");
console.log("WeakSet has objectTwo : " +
weakSetObject.has(objectTwo));

Output:

objectOne added 
objectTwo added 
WeakSet has objectTwo : true
objectTwo deleted
WeakSet has objectTwo : false

Supported Browsers:

• Google Chrome
• Internet Explorer
• Firefox
• Apple Safari
• Opera

We have a complete list of Javascript weakSet methods, to check those please go through this JavaScript WeakSet Reference article.