JavaScript - For Loop

The 'for' loop is the most compact form of looping. It includes the following three important parts −

·        The loop initialization where we initialize our counter to a starting value. The initialization statement is executed before the loop begins.

·        The test statement which will test if a given condition is true or not. If the condition is true, then the code given inside the loop will be executed, otherwise the control will come out of the loop.

·        The iteration statement where you can increase or decrease your counter.

You can put all the three parts in a single line separated by semicolons.

Flow Chart

The flow chart of a for loop in JavaScript would be as follows −

For Loop

Syntax

The syntax of for loop is JavaScript is as follows −

for (initialization; test condition; iteration statement){

   Statement(s) to be executed if test condition is true

}

Example

Try the following example to learn how a for loop works in JavaScript.

<html>

   <body>

     

      <script type="text/javascript">

         <!--

            var count;

            document.write("Starting Loop" + "<br />");

        

            for(count = 0; count < 10; count++){

               document.write("Current Count : " + count );

               document.write("<br />");

            }

        

            document.write("Loop stopped!");

         //-->

      </script>

     

      <p>Set the variable to different value and then try...</p>

   </body>

</html>

Output

Starting Loop

Current Count : 0

Current Count : 1

Current Count : 2

Current Count : 3

Current Count : 4

Current Count : 5

Current Count : 6

Current Count : 7

Current Count : 8

Current Count : 9

Loop stopped!

Set the variable to different value and then try...