JavaScript Array forEach() Method
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>
The result will be:
index[0]: 4
index[1]: 9
index[2]: 16
index[3]: 25
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 | 12.0 | 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:
|
||||||||
| 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: | 1.6 |
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
