DOMTokenList: contains() method

Baseline Widely available

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

The contains() method of the DOMTokenList interface returns a boolean value — true if the underlying list contains the given token, otherwise false.

Syntax

js
contains(token)

Parameters

token

A string representing the token you want to check for the existence of in the list.

Return value

A boolean value, which is true if the calling list contains token, otherwise false.

Examples

In the following example we retrieve the list of classes set on a <span> element as a DOMTokenList using Element.classList. We then test for the existence of "c" in the list, and write the result into the <span>'s Node.textContent.

First, the HTML:

html
<span class="a b c"></span>

Now the JavaScript:

js
const span = document.querySelector("span");
span.textContent = span.classList.contains("c")
  ? "The classList contains 'c'"
  : "The classList does not contain 'c'";

The output looks like this:

Specifications

Specification
DOM
# ref-for-dom-domtokenlist-contains①

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
contains
Chrome – Full support
Chrome 8 (Release date: 2010-12-02)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 3.6 (Release date: 2010-01-21)
footnote Full support
Opera – Full support
Opera 12.1 (Release date: 2012-11-20)
footnote Full support
Safari – Full support
Safari 5.1 (Release date: 2011-07-20)
footnote Full support
Chrome Android – Full support
Chrome Android 18 (Release date: 2012-06-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 4 (Release date: 2011-03-29)
footnote Full support
Opera Android – Full support
Opera Android 12.1 (Release date: 2012-10-09)
footnote Full support
Safari on iOS – Full support
Safari on iOS 5 (Release date: 2011-10-12)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1 (Release date: 2013-04-27)
footnote Full support
WebView Android – Full support
WebView Android 3 (Release date: 2011-02-22)
footnote Full support
WebView on iOS – Full support
WebView on iOS 5 (Release date: 2011-10-12)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support