switch: Picking from Many Options

When you have many exact values

When you compare one variable against many exact values, switch is cleaner than a long else if chain:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int day = sc.nextInt();
        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            default:
                System.out.println("Some other day");
        }
    }
}

Input (what the user types)

2

Output

Tuesday

• Each case is one possible value.
• break means “stop here and leave the switch”.
• default runs when no case matches (like else).

Forgetting break

Without break, Java keeps running into the next cases. This is called fall-through:

public class Main {
    public static void main(String[] args) {
        int level = 2;
        switch (level) {
            case 1:
                System.out.println("Bronze");
            case 2:
                System.out.println("Silver");
            case 3:
                System.out.println("Gold");
        }
    }
}

Output

Silver
Gold

Sometimes fall-through is useful – several cases can share the same code:

public class Main {
    public static void main(String[] args) {
        String fruit = "mango";
        switch (fruit) {
            case "apple":
            case "mango":
            case "banana":
                System.out.println(fruit + " is a fruit");
                break;
            case "carrot":
                System.out.println(fruit + " is a vegetable");
                break;
            default:
                System.out.println("I don't know " + fruit);
        }
    }
}

Output

mango is a fruit

Remember: switch works with int, char, String and enums – but not with double or boolean.