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DOMTokenList: contains() method

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

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
contains 8 12 3.6 10 ≤12.1 5.1 3 18 4 ≤12.1 5 1.0

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https://developer.mozilla.org/en-US/docs/Web/API/DOMTokenList/contains