The keys()
method of the DOMTokenList
interface returns an iterator
allowing to go through
all keys contained in this object. The keys are of type unsigned integer
.
Syntax
tokenList.keys();
Parameters
None.
Return value
Returns an iterator
.
Examples
In the following example we retrieve the list of classes set on a
<span>
element as a DOMTokenList
using
Element.classList
. We when retrieve an iterator containing the keys using
values()
, then iterate through those keys using a for ... of loop,
writing each one to the <span>
's Node.textContent
.
First, the HTML:
<span class="a b c"></span>
Now the JavaScript:
var span = document.querySelector("span");
var classes = span.classList;
var iterator = classes.keys();
for(var value of iterator) {
span.textContent += value + ' ++ ';
}
The output looks like this:
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'keys() (as iterable<Node>)' in that specification. |
Living Standard | Initial definition |
Browser compatibility
BCD tables only load in the browser