Web/API/NodeList/forEach

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

Syntax

someNodeList.forEach(callback[, thisArg]);

Parameters

callback: A function to execute on each element of someNodeList. It accepts 3 parameters:

currentValue The current element being processed in someNodeList. currentIndex Optional The index of the currentValue being processed in someNodeList. listObj Optional The someNodeList that forEach() is being applied to.

thisArg Optional: Value to use as this when executing callback.

Return value

undefined.

Example

let node = document.createElement("div");
let kid1 = document.createElement("p");
let kid2 = document.createTextNode("hey");
let kid3 = document.createElement("span");

node.appendChild(kid1);
node.appendChild(kid2);
node.appendChild(kid3);

let list = node.childNodes;

list.forEach( 
  function(currentValue, currentIndex, listObj) { 
    console.log(currentValue + ', ' + currentIndex + ', ' + this); 
  },
  'myThisArg'
);

The above code results in the following:

[object HTMLParagraphElement], 0, myThisArg
[object Text], 1, myThisArg
[object HTMLSpanElement], 2, myThisArg

Polyfill

This polyfill adds compatibility to all Browsers supporting ES5:

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

OR

if (window.NodeList && !NodeList.prototype.forEach) {
   NodeList.prototype.forEach = Array.prototype.forEach;
}

The above behavior is how many browsers actually implement NodeList.prototype.forEach() (Chrome, for example).

Specifications

Specification	Status	Comment
Web IDLThe definition of 'forEach' in that specification.	Candidate Recommendation	Defines `forEach` on `iterable` declarations

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 51	Edge Full support 16	Firefox Full support 50	IE No support No	Opera Full support 38	Safari Full support 10	WebView Android Full support 51	Chrome Android Full support 51	Firefox Android Full support 50	Opera Android Full support 41	Safari iOS Full support 10	Samsung Internet Android Full support 5.0

Legend

Full support: Full support
No support: No support