---
title: JavaScript for Loops Explained
---
The for statement creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement or a set of statements executed in the loop.
The for loop has the following syntax:
for (initialization]; [condition]; [final-expression]) {
code block to be executed
}
[initialization] is executed before the loop (the code block) starts.
[condition] defines the condition for running the loop (the code block).
[final-expression] is executed each time after the loop (the code block) has been executed.
## Example in JavaScript:
var ourArray = [];
for (var i = 0; i < 5; i++) {
ourArray.push(i);
}
From the example above, you can read:
[initialization] sets a variable before the loop starts (var i = 0).
[condition] defines the condition for the loop to run (i must be less than 5).
[final-expression] increases a value (i++) each time the code block in the loop has been executed.
## Why we need "for loops"?
For loops are used to loop through a block of code a known number of times. Sometimes it is the computer that knows how many times, not you, but it is still known.
Checkout some of our other articles on loops:
* [While Loop
* For In Loop