Loops in JAVA

Loops let you repeat a block of code multiple times.

They are used when you want to run the same code until a condition is false.

Used when the number of iterations is known.

🔸 Syntax:

for(initialization; condition; update) {
    // code to repeat
}

🔸 Code Example:

for (int i = 1; i <= 5; i++) {
    System.out.println("Count: " + i);
}

Count: 1
Count: 2
Count: 3
Count: 4
Count: 5

🔍 Why use it?

When you know exactly how many times you want to loop.

Used when the condition is checked before every iteration.

Ideal for situations where you don’t know how many times you'll loop.

🔸 Code Example:

int i = 1;

while (i <= 3) {
    System.out.println("i = " + i);
    i++;
}

i = 1
i = 2
i = 3

🔍 Why use it?

When you want to loop based on a condition being true.

Same as while loop, but it runs at least once, even if the condition is false.

🔸 Code Example:

int i = 1;

do {
    System.out.println("Value is: " + i);
    i++;
} while (i <= 2);

Value is: 1
Value is: 2

🔍 Why use it?

Use when the code should execute at least once, no matter what.

Feature	`for` loop	`while` loop	`do-while` loop
Control Type	✅ Entry-controlled	✅ Entry-controlled	✅ Exit-controlled
When condition is checked?	✅ Before the loop starts	✅ Before the loop starts	✅ After the loop executes once
Minimum executions	0 times (may not run at all)	0 times (may not run at all)	At least once (even if condition is false)
Use case	When number of iterations is known	When number of iterations is unknown	When loop must run at least once
Syntax	`for(init; cond; update) {}`	`while(condition) {}`	`do { } while(condition);`