How to create for loop in Javascript

Description

The for statement's syntax:

for (initialization; expression; post-loop-expression) 
    statement

A common implementation initializes a counting variable, i; increments the value of i by 1 each time; and repeats the loop until the value of i exceeds some maximum value:

for (var i = startValue;i <= maxValue;i++) 
{ 
   statements;
}

Example

And here's an example of its usage:

var count = 10; 
for (var i=0; i < count; i++){ 
   document.writeln(i); 
} 

The code above generates the following result.

This for loop is the same as the following:

var count = 10; //from   w  w  w .ja  va  2  s  . c o  m
var i = 0; 
while (i < count){
   document.writeln(i); 
   i++; 
} 

Note

There's no need to use the var inside the for loop initialization.

var count = 10;
var i;
for (i=0; i < count; i++){
    console.log(i);
}

There are no block-level variables in Javascript.

Example 2

The initialization, control expression, and postloop expression are all optional.

var count = 10; 
var i = 0; 
for (; i < count; ){//  w w w .  j  ava 2  s.co  m
    console.log(i); 
    i++; 
} 

The code above generates the following result.