NodeList.prototype.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

NodeList.forEach(callback[, thisArg]);

Parameters

callback

Function to execute for each element, eventually taking 3 arguments:

currentValue

The current element being processed in the NodeList.

currentIndex

The index of the current element being processed in the NodeList.

listObj

The NodeList object that forEach() is being applied to.

thisArg Optional

Value to use as this when executing callback.

Return value

undefined.

Exceptions

None.

Example

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

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

var list = node.childNodes;

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

results in:

[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

Browser Compatibility

See also

• Node
• NodeList