Switch case

Source: Dev.to

Overview

• A switch case is a control statement that lets you run different blocks of code based on the value of a variable or expression.
• It is often cleaner and easier to read than writing many if–else statements.
• In Java, the switch statement works with primitive types int, byte, short, char and, since Java 8, with String.
• Starting with Java 12, the arrow syntax (->) can be used as a more concise alternative to break.

Syntax

switch (expression) {
    case value1:
        // statements
        break;               // stops fall‑through
    case value2 ->          // arrow syntax (Java 12+)
        // statements
    default:
        // default statements
}

• break; stops execution after the matched case block.
• Arrow syntax (->) automatically prevents fall‑through, so an explicit break is not needed.

Example 1 – Switching on an int

public class SwitchCaseExample {
    public static void main(String[] args) {
        int day = 5;   // can be int, byte, short, or char

        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("Holiday");
        }
    }
}

Example 2 – Switching on a String (Java 8+)

package moduleTwo;

public class SwitchCaseTest {
    public static void main(String[] args) {
        String say = "hello";

        switch (say) {
            case "hi":
                System.out.println("hey");
                break;
            case "hello":
                System.out.println("Good morning");
                break;
            default:
                System.out.println("unknown");
        }
    }
}

Example 3 – Multiple Labels and Arrow Syntax (Java 12+)

public class SwitchCaseTest {
    public static void main(String[] args) {
        String grade = "B";

        switch (grade) {
            case "A", "B" -> System.out.println("pass");
            case "C"       -> System.out.println("fail");
            default        -> System.out.println("no result");
        }
    }
}