The keys()
method of the DOMTokenList
interface returns an iterator allowing to go through all keys contained in this object. The keys are unsigned integers.
The keys()
method of the DOMTokenList
interface returns an iterator allowing to go through all keys contained in this object. The keys are unsigned integers.
js
keys()
None.
Returns an iterator.
In the following example we retrieve the list of classes set on a <span>
element as a DOMTokenList
using Element.classList
. We then retrieve an iterator containing the keys using keys()
, then iterate through those keys using a for...of loop, writing each one 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 iterator = classes.keys(); for (let value of iterator) { span.textContent += `(${value}) `; }
The output looks like this:
No specification data found for api.DOMTokenList.keys
.
Check for problems with this page or contribute a missing spec_url
to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
keys |
42 | 16 | 50 | No | 29 | 10.1 | 42 | 42 | 50 | 29 | 10.3 | 4.0 |
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https://developer.mozilla.org/en-US/docs/Web/API/DOMTokenList/keys