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
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:
<span class="a b c"></span>
Now the JavaScript:
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 Standard # ref-for-dom-domtokenlist-contains① |
Browser compatibility
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