09_Loops

Loops

What is a Loop?

A loop allows us to execute a block of code MULTIPLE TIMES based on a condition.

Instead of writing the same lines again and again, loops make code **shorter**, **efficient**, and **less error-prone**.

Why Do We Need Loops?

Imagine we want to print a name 100 times, without a LOOP, we have to write -

System.out.println("Athira");
System.out.println("Athira");
System.out.println("Athira");

// ... and so on, 100 times             Very lengthy and hard to maintain!

With Loop

 We can automate repetition efficiently.


(1) Define where to start (initialization),

(2) Set a condition to continue running,

(3) And decide how many times to repeat.

This way, we write less code, avoid repetition, and make our programs clean and maintainable.

Types of Loops in Java

Java provides three main types of loops:


| Loop Type       | Description                                                 |
| --------------- | ----------------------------------------------------------- |
| FOR loop        | Used when the number of iterations is KNOWN in advance.     |
| WHILE loop      | Used when the number of iterations is NOT KNOWN ahead.      |
| DO-WHILE loop   | Similar to WHILE, but EXCECUTES ATLEAST ONCE                |

Loop Structure

All loops involve these key components:



1️  Initialization   → Setting up the starting point  

2️. Condition        → When to stop the loop  

3️.  Update/Increment → Progressing toward the stop condition  

4️.  Body             → The code we want to repeat