The for Loop

Counting made neat

When you know how many times to repeat, a for loop puts everything in one line:

public class Main {
    public static void main(String[] args) {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Lap " + i);
        }
    }
}

Output

Lap 1
Lap 2
Lap 3
Lap 4
Lap 5

The three parts inside the brackets, separated by ;:

Counting in other ways

public class Main {
    public static void main(String[] args) {
        for (int i = 10; i >= 1; i--) {
            System.out.print(i + " ");
        }
        System.out.println("Lift off!");

        for (int i = 0; i <= 20; i += 5) {
            System.out.print(i + " ");
        }
        System.out.println();
    }
}

Output

10 9 8 7 6 5 4 3 2 1 Lift off!
0 5 10 15 20 

A times table

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        for (int i = 1; i <= 5; i++) {
            System.out.println(n + " x " + i + " = " + (n * i));
        }
    }
}

Input (what the user types)

7

Output

7 x 1 = 7
7 x 2 = 14
7 x 3 = 21
7 x 4 = 28
7 x 5 = 35

Tip: Use for when you know how many times to repeat. Use while when you repeat until something happens.