Docs4dev
Docs
javascript / latest / global_objects / set / set.html

Set() constructor

The Set() constructor creates Set objects.

Try it

Syntax

js 
new Set()
new Set(iterable)

Note: Set() can only be constructed with new. Attempting to call it without new throws a TypeError.

Parameters

iterable Optional

If an iterable object is passed, all of its elements will be added to the new Set.

If you don't specify this parameter, or its value is null, the new Set is empty.

Return value

A new Set object.

Examples

Using the Set object

js 
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);

Specifications

Specification
ECMAScript Language Specification
# sec-set-constructor

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android Deno Node.js
Set 38 12 13 25 8 38 14 25 8 3.0 38 1.0 0.12.0
iterable_allowed 38 12 13 25 9 38 14 25 9 3.0 38 1.0 0.12.0
new_required 38 12 42 25 9 38 42 25 9 3.0 38 1.0 0.12.0
null_allowed 38 12 37 25 9 38 37 25 9 3.0 38 1.0 0.12.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/Set