JavaScript Set add() Method

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 38 and above
• Edge 12 and above
• Firefox 24 and above
• Opera 25 and above
• Safari 8 and above

We have a complete list of Javascript Set methods, to check those please go through this Sets in JavaScript article.

We have a Cheat Sheet on Javascript where we covered all the important topics of Javascript to check those please go through Javascript Cheat Sheet-A Basic guide to JavaScript.