Array forEach

In this chapter you will learn:

How to use Javascript array forEach function

Array forEach()

forEach() accepts two arguments:

a function to run on each item and
an optional scope object

forEach() runs the given function on every item in the array. forEach() has no return value.

The function passed in receives three arguments:

the array item value,
the position of the item in the array
the array object itself.

It is the same as iterating over an array with a for loop.

<!DOCTYPE html><!--   j a  v a 2s.c o  m-->
<html>
<head>
    <script type="text/javascript">
        var numbers = [1,2,3,4,5,4,3,2,1]; 
        
        numbers.forEach(function(item, index, array){ 
            document.writeln(item);
        }); 
        //
    </script>
</head>
<body>
</body>
</html>

Click to view the demo

The code above generates the following result.

forEach() does not change the values contained in the array.

Next chapter...

What you will learn in the next chapter:

How to use array as a stack
How to use push and index to add value to an array

Array forEach

Array forEach()

Next chapter...

Array Type

Array creation

Array type detecting

Array iterate

Array Length

Add to Array

Array join

Array concat()

Array every method

Array search from start with indexOf()

Array search from the end with lastIndexOf()

Array filter

Array mapping

Array forEach

Array pop and push

Array shift()

Array reduce()

Array reduceRight()

Array reverse()

Array slice()

Array some()

Array splice()

Array sort()

Array toString()

Array unshift()