Operators aur Control Flow

if aur else waise hi kaam karte hain jaisa aap kisi bhi C-family language se expect karoge — parentheses mein ek condition, uske baad ek block.

Main.java

Khud try karo →

public class Main {
    public static void main(String[] args) {
        int number = 7;
        if (number % 2 == 0) {
            System.out.println(number + " is even");
        } else {
            System.out.println(number + " is odd");
        }
    }
}

Output

7 is odd

for aur while

Ek classic for loop apne header mein ek index, ek condition, aur ek increment, teenon declare karta hai. while bas tab tak repeat karta hai jab tak uski condition true rahe, bina kisi built-in index ke.

Main.java

Khud try karo →

public class Main {
    public static void main(String[] args) {
        for (int i = 0; i < 3; i++) {
            System.out.println("i = " + i);
        }
        int count = 0;
        while (count < 3) {
            System.out.println("count = " + count);
            count++;
        }
    }
}

Output

i = 0
i = 1
i = 2
count = 0
count = 1
count = 2

switch

switch ek value ko constant cases ki ek series se compare karta hai, aur break na karne par agle case mein fall through kar jaata hai. default us cheez ko catch karta hai jo upar match nahi hui.

Main.java

Khud try karo →

public class Main {
    public static void main(String[] args) {
        int day = 3;
        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            default:
                System.out.println("Unknown");
        }
    }
}

Output

Wednesday

Aage: methods — methods define karna, parameters, return types, aur method overloading.

Practice exercise

Ek variable score, type int ka, 73 par set karo. "pass" print karo agar score 60 ya usse zyada ho, warna "fail" print karo.

← Variables aur Types Methods →