🧠 What is a Loop?

Loop = Repeat a block of code multiple times until a condition is met.

C++ supports three main types of loops:

Loop Type When to Use
for When number of repetitions is known
while When number of repetitions is unknown
do-while When loop must run at least once

🔁 Why Use Loops?

Imagine printing "Hello World" 10 times:

❌ Without Loop:


cout << "Hello World\n";
cout << "Hello World\n";
// repeat 10 times 😫

✅ With Loop:


for(int i = 0; i < 10; i++) {
    cout << "Hello World\n";
}

Much cleaner and faster to write!

🔍 Loop Structure Summary

Loop Type Structure
for for(init; condition; update) { // code }
while while(condition) { // code }
do-while do { // code } while(condition);

🔸 Real-Life Examples:

Scenario Use Loop?
Printing numbers 1 to 100 ✅ Yes
Keep asking for password until correct ✅ Yes
Run a menu-driven program (like calculator) ✅ Yes

🎯 Output Example: