DOMTokenList: length property

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 read-only length property of the DOMTokenList interface is an integer representing the number of objects stored in the object.

Value

An positive integer, or 0 if the list is empty.

Examples

In the following example we retrieve the list of classes set on a <span> element as a DOMTokenList using Element.classList, then write the length of the list to the <span>'s Node.textContent.

First, the HTML:

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

Now the JavaScript:

js
const span = document.querySelector("span");
const classes = span.classList;
const length = classes.length;

span.textContent = `classList length = ${length}`;

The output looks like this:

Specifications

Specification
DOM
# ref-for-dom-domtokenlist-length①

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
length

Legend

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Full support
Full support