Set() constructor

BaselineWidely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

TheSet() constructor createsSet objects.

Try it

const set1 = new Set([1, 2, 3, 4, 5]);console.log(set1.has(1));// Expected output: trueconsole.log(set1.has(5));// Expected output: trueconsole.log(set1.has(6));// Expected output: false

Syntax

new Set()new Set(iterable)

Note:Set() can only be constructed withnew. Attempting to call it withoutnew throws aTypeError.

Parameters

iterableOptional

If aniterable object is passed, all of its elements will be added to the newSet.

If you don't specify this parameter, or its value isnull, the newSet is empty.

Return value

A newSet object.

Examples

Using the`Set` object

const mySet = new Set();mySet.add(1); // Set [ 1 ]mySet.add(5); // Set [ 1, 5 ]mySet.add(5); // Set [ 1, 5 ]mySet.add("some text"); // Set [ 1, 5, 'some text' ]const o = { a: 1, b: 2 };mySet.add(o);