Introduction to For Loops

Introduction to For Loops in JavaScript

When you want to repeat a block of code multiple times, instead of writing it again and again, you use loops. The most common loop is the for loop.

What is a For Loop?

A for loop runs a block of code a specific number of times — great for going through arrays, counting, or repeating tasks.

Basic Syntax of a For Loop

• Initialization: Start point (usually a counter variable)

• Condition: Runs the loop while this is true

• Update: What happens after each loop iteration (e.g., increment counter)

Example: Counting from 1 to 5

Output:

Breaking Down the Example

• let i = 1; — Start counting at 1

• i <= 5; — Continue loop as long as i is less than or equal to 5

• i++ — Increase i by 1 each time (same as i = i + 1)

Using For Loops with Arrays

You can loop through an array’s elements like this:

Output:

Why Use For Loops?

• Automate repetitive tasks

• Process every item in a list or array

• Write cleaner, shorter code

Summary