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 Boolean, 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:

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

Now the JavaScript:

let span = document.querySelector("span");
let classes = span.classList;
let 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

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
containsChrome Full support 8Edge Full support 12Firefox Full support YesIE Full support 10Opera Full support YesSafari Full support 5.1WebView Android Full support 3Chrome Android Full support 18Firefox Android Full support YesOpera Android Full support YesSafari iOS Full support 5.1Samsung Internet Android Full support 1.0

Legend

Full support  
Full support