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.