Set methodsBaseline · Newly available

The difference(), intersection(), isDisjointFrom(), isSubsetOf(), isSupersetOf(), symmetricDifference(), and union() methods of the JavaScript Set object performs operations between two sets.

Works in the latest version of every major browser, but older devices may not support it yet. Baseline since Jun 11, 2024.

How to use ↓Compare browsers

Browser support

DesktopChrome

1–121Not supported

122+Supportedsince Feb 20, 2024

Current: 155

Edge

12–121Not supported

122+Supportedsince Feb 23, 2024

Current: 154

Firefox

1–126Not supported

127+Supportedsince Jun 11, 2024

Current: 157

Safari

1–16.6Not supported

17+Supportedsince Sep 18, 2023

Current: 27

MobileChrome Android

18–121Not supported

122+Supportedsince Feb 20, 2024

Current: 155

Firefox Android

4–126Not supported

127+Supportedsince Jun 11, 2024

Current: 157

Safari iOS

1–16.6Not supported

17+Supportedsince Sep 18, 2023

Current: 27

How to use

Every current browser supports this, but it only became Baseline on Jun 11, 2024. Use it as a progressive enhancement, or keep a fallback if you support older devices.

Example

const a = new Set([1, 2, 3]);
const b = new Set([2, 3, 4]);

a.union(b);               // Set {1, 2, 3, 4}
a.intersection(b);        // Set {2, 3}
a.difference(b);          // Set {1}
a.isSubsetOf(new Set([1, 2, 3, 4])); // true

Feature detection

JS · check before using

if ("difference" in Set || ("prototype" in Set && "difference" in Set.prototype)) {
  // Set.difference is available
}

Documentation (MDN)

Specification

tc39.es#sec-properties-of-the-set-prototype-object ↗

Sub-features

Support for each part of the feature (7). The overall table above shows when the whole feature works.

Sub-feature	Chrome	Edge	Firefox	Safari	Chrome Android	Firefox Android	Safari iOS
Set.difference	122	122	127	17	122	127	17
Set.intersection	122	122	127	17	122	127	17
Set.isDisjointFrom	122	122	127	17	122	127	17
Set.isSubsetOf	122	122	127	17	122	127	17
Set.isSupersetOf	122	122	127	17	122	127	17
Set.symmetricDifference	122	122	127	17	122	127	17
Set.union	122	122	127	17	122	127	17