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
A 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 |