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JavaScript Array forEach() Method

❮ JavaScript Array Reference

Example

List each item in the array:

<button onclick="numbers.forEach(myFunction)">Try it</button>
<p id="demo"></p>

<script>
demoP = document.getElementById("demo");
var numbers = [4, 9, 16, 25];

function myFunction(item, index) {
    demoP.innerHTML = demoP.innerHTML + "index[" + index + "]: " + item + "<br>";
}
</script>
Try it Yourself »

More "Try it Yourself" examples below.


Definition and Usage

The forEach() method calls a provided function once for each element in an array, in order.

Note: forEach() does not execute the function for array elements without values.


Browser Support

The numbers in the table specify the first browser version that fully supports the method.

Method
forEach() Yes 9.0 1.5 Yes Yes

Syntax

array.forEach(function(currentValue, index, arr), thisValue)

Parameter Values

Parameter Description
function(currentValue, index, arr) Required. A function to be run for each element in the array.
Function arguments:
Argument Description
currentValue Required. The value of the current element
index Optional. The array index of the current element
arr Optional. The array object the current element belongs to
thisValue Optional. A value to be passed to the function to be used as its "this" value.
If this parameter is empty, the value "undefined" will be passed as its "this" value


Technical Details

Return Value: undefined
JavaScript Version: ECMAScript 3

More Examples

Example

Get the sum of all the values in the array:

<button onclick="numbers.forEach(myFunction)">Try it</button>

<p>Sum of numbers in array: <span id="demo"></span></p>

<script>
var sum = 0;
var numbers = [65, 44, 12, 4];

function myFunction(item) {
    sum += item;
    demo.innerHTML = sum;
}
</script>
Try it Yourself »

Example

Multiply all the values in array with a specific number:

<p>Multiply with: <input type="number" id="multiplyWith" value="10"></p>
<button onclick="numbers.forEach(myFunction)">Try it</button>

<p>Updated array: <span id="demo"></span></p>

<script>
var numbers = [65, 44, 12, 4];

function myFunction(item, index, arr) {
    arr[index] = item * document.getElementById("multiplyWith").value;
    demo.innerHTML = numbers;
}
</script>
Try it Yourself »

❮ JavaScript Array Reference