JavaScript WeakSet() Constructor

JavaScript WeakSet Constructor is used to create a weakset that is similar to the set as it does not contain duplicate objects. It is different from the set as it stores a collection of weakly held objects instead of an object of a particular type.

We can only create a WeakSet with the new keyword otherwise a TypeError will be thrown

Syntax:

new WeakSet()
new WeakSet(iter)

Parameter: It has one optional parameter.

• iter: It is an iterable object whose elements will be assigned to new WeakSet. If null is given it will be treated as undefined.

Return Type: A WeakSet object

Example 1: In this example, we will create a WeakSet object and add elements to it.

let x = new WeakSet();
let y = new WeakSet(null);
x.add({});
x.add({});
console.log(x);
console.log(y);

Output:

WeakSet {{…}, {…}}
WeakSet {}

Example 2: In this example, we will add objects with values in WeakSet and check if the element is inserted with inbuilt methods.

let looseSet = new WeakSet();
let Rahul = {name: "Rahul"};
let Vijay = {name: "Vijay"}
let Ram = {name: "Ram"}
looseSet.add(Rahul);
looseSet.add(Vijay);

console.log(looseSet.has(Rahul)); // true
console.log(looseSet.has(Ram)); // false

Output:

true
false

Supported Browsers:

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

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