Open In App

JavaScript Set add() Method

Last Updated : 23 Jul, 2025
Suggest changes
Share
Like Article
Like
Report

The Set.add() method in JavaScript is used to append an element with a specified value in a set. It modifies the existing set by appending the new element but does not return a new set. The Set.add() method does not modify the set if the element with a specified value already exists in the set.

Syntax:

mySet.add(value);

Parameters:

  • value: It is the value of the new element that is about to get appended to our set.

Return value:

  • It returns the set object with an added value

Example 1: In this example, we have added two numbers 23 and 12 into the set.

JavaScript
// Create a new set using Set() constructor let myset = new Set(); // Append new elements to the  // set using add() method myset.add(23); myset.add(12); // Print the modified set console.log(myset);  

Output
Set(2) { 23, 12 } 

Example 2: Adding elements using add() with chaining and checking if duplicate values exist or not.

JavaScript
// Create a new set using Set() constructor let myset = new Set(); // Append new elements to the set  // using add() method with chaining myset.add(23).add(12); // Appending an already existing  // element to the set this // element will not be added to the set  // as it contains only distinct elements myset.add(23); // Print the modified set console.log(myset); 

Output
Set(2) { 23, 12 } 

 Supported Browsers:

  • Chrome
  • Edge
  • Firefox
  • Opera
  • Safari

Explore