MDN wants to talk to developers like you: https://qsurvey.mozilla.com/s3/8d22564490d8

DOMTokenList.contains()

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

Syntax

tokenList.contains(token);

Parameters

token
A DOMString representing the token you want to check for the existance of in the list.

Return value

A Booleantrue if the underlying list contains the given 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 existance of "c" in the list, and write the result into the <span>'s Node.textContent.

First, the HTML:

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

Now the JavaScript:

var span = document.querySelector("span");
var classes = span.classList;
var result = classes.contains("c");
if(result) {
  span.textContent = "The classList contains 'c'";
} else {
   span.textContent = "The classList does not contain 'c'";
}

The output looks like this:

Specifications

Specification Status Comment
DOM
The definition of 'contains()' in that specification.
Living Standard Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) (Yes) 10 (Yes) (Yes)
Feature Android Webview Chrome for Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) ? (Yes)

 

Document Tags and Contributors

 Contributors to this page: chrisdavidmills
 Last updated by: chrisdavidmills,