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 insomeNodeList
. listObj
Optional- The
someNodeList
thatforEach()
is being applied to.
thisArg
Optional- Value to use as
this
when executingcallback
.
Return value
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 IDL The definition of 'forEach' in that specification. |
Candidate Recommendation | Defines forEach on iterable declarations |
Browser Compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
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