JavaScript Array forEach() Method

Below is the example of the Array forEach() method.

  • Example:
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    <script>
        // JavaScript to illustrate forEach() method
        function func() {
          
            // Original array
            const items = [12, 24, 36];
            const copy = [];
      
            items.forEach(function (item) {
                copy.push(item + item+2);
            });
      
            document.write(copy);
        }
        func();
    </script>                    

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  • Output:
    26,50,74

The arr.forEach() method calls the provided function once for each element of the array. The provided function may perform any kind of operation on the elements of the given array.

Syntax:

array.forEach(callback(element, index, arr), thisValue)

Parameters: This method accepts five parameters as mentioned above and described below:

  • callback: This parameter holds the function to be called for each element of the array.
  • element: The parameter holds the value of the elements being processed currently.
  • index: This parameter is optional, it holds the index of the current value element in the array starting from 0.
  • array: This parameter is optional, it holds the complete array on which Array.every is called.
  • thisArg: This parameter is optional, it holds the context to be passed as this to be used while executing the callback function. If the context is passed, it will be used like this for each invocation of the callback function, otherwise undefined is used as default.

Return value: The return value of this method is always undefined. This method may or may not change the original array provided as it depends upon the functionality of the argument function.



Below example illustrate the Array forEach() method in JavaScript:

  • Example: In this example the method forEach() calculates the square of every element of the array.
    const items = [1, 29, 47];
    const copy = [];
    
    items.forEach(function(item){
      copy.push(item*item);
    });
    print(copy);
    

    Output:

    1,841,2209

Code for the above method is provided below:

Program:

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edit
close

play_arrow

link
brightness_4
code

<script>
    // JavaScript to illustrate forEach() method
    function func() {
        
        // Original array
        const items = [1, 29, 47];
        const copy = [];
  
        items.forEach(function (item) {
            copy.push(item * item);
        });
  
        document.write(copy);
    }
    func();
</script>

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Output:

1,841,2209

Supported Browsers: The browsers supported by JavaScript Array forEach() method are listed below:

  • Google Chrome
  • Microsoft Edge 9.0
  • Mozilla Firefox 1.5
  • Safari
  • Opera

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