Web/API/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 [, thisArg]);

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.

thisArg 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.

HTML

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

JavaScript

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

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

Result

Polyfill

This polyfill adds compatibility to all Browsers supporting ES5:

if (window.DOMTokenList && !DOMTokenList.prototype.forEach) {
  DOMTokenList.prototype.forEach = function (callback, thisArg) {
    thisArg = thisArg || window;
    for (var i = 0; i < this.length; i++) {
      callback.call(thisArg, this[i], i, this);
    }
  };
}

Specifications

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

Browser Compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`forEach`	Chrome Full support 42	Edge Full support 16	Firefox Full support 50	IE No support No	Opera Full support 32	Safari Full support 10.1	WebView Android Full support 45	Chrome Android Full support 45	Firefox Android Full support 50	Opera Android Full support 32	Safari iOS Full support 10.3	Samsung Internet Android Full support 5.0

Legend

Full support: Full support
No support: No support