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DOMTokenList.forEach()

The forEach() method of the DOMTokenList interface calls the callback given in parameter once for each value pair in the list, in insertion order.

Syntax

tokenList.forEach(callback);
tokenList.forEach(callback, argument);

Parameters

callback
Function to execute for each element, eventually taking three arguments:
currentValue
The current element being processed in the array.
currentIndex
The index of the current element being processed in the array.
listObj
The array that forEach() is being applied to.
argument Optional
Value to use as this when executing callback.

Return value

undefined.

Example

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 values using forEach(), writing each one to the <span>'s Node.textContent inside the forEach() inner function.

First, the HTML:

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

Now the JavaScript:

var span = document.querySelector("span");
var classes = span.classList;
var iterator = classes.values();

classes.forEach(
  function(value, key, listObj) {
    span.textContent += value + ' ' + key + "/" + this + '  ++  ';
  },
  "arg"
);

The output looks like this:

Specifications

Specification Status Comment
DOM
The definition of 'forEach() (as iterable<Node>)' in that specification.
Living Standard Initial definition.

Browser Compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) No support 50 (50) ? (Yes) ?
Feature Android Android Webview Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support (Yes) 50.0 (50) ? (Yes) ? (Yes)

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, farv, teoli
 Last updated by: chrisdavidmills,