Q:

How to forEach Over an Array in JavaScript

mhmadesk
Save to bookmark
|
2022-05-18
|
  277 
Very Easy
0

How to forEach Over an Array in JavaScript

JavaScript programming,
login and add your own answer to this question

All Answers

mhmadesk
2022-05-18
need an explanation for this answer? contact us directly to get an explanation for this answer

Use the forEach() Method

You can simply use the array's forEach() method to loop through all the items in an array using JavaScript. The forEach() method executes a provided function once for each array element.

The following example will display all the values in the cities array using foreach loop.

<script>
    // Sample array
    var cities = ["London", "Paris", "New York", "Amsterdam"];
    
    // Loop over array
    cities.forEach(function(value){
        document.write("<p>" + value + "</p>");
    });
</script>

The forEach() method does not modify the original array (i.e. the array on which it is called). However, the callback function, if invoked, may do so. The following example will modify the given array by squaring each of its value (multiplying it by itself).

<script>
    // Sample array
    var numbers = [1, 2, 3, 4, 5, 6];
    
    // Loop over array and squaring each value
    numbers.forEach(function(value, index, array){
        array[index] = value * value;
    });
    
    console.log(numbers); // Prints: [1, 4, 9, 16, 25, 36]
</script>

The basic syntax of the forEach() method can be given with arr.forEach(function callback(value, index, array){ // your iterator }. The callback function is invoked with three arguments: the element value, the element index, and the array being traversed.

The forEach() was added to the ECMAScript standard in the 5th edition. This method is supported in all major modern browsers, such as Chrome, Firefox, IE9+, etc.

need an explanation for this answer? contact us directly to get an explanation for this answer

total answers (1)

JavaScript / jQuery Frequently Asked Questions
This question belongs to these collections

Similar questions

need a help?

find thousands of online teachers now
How to Check If an Input Field is Empty Using jQue... >>
<< How to Detect Change in a Text Input Box in jQuery...