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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

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
containsChrome Full support 1Edge Full support 12Firefox Full support YesIE Full support 10Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile ? Firefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

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