Instrukcje switch

Dlaczego switch

Składnia klasyczna

public class Main {
    public static void main(String[] args) {
        int n = 2;

        switch (n) {
            case 1:
                System.out.println("one");
                break;
            case 2:
                System.out.println("two");
                break;
            default:
                System.out.println("other");
        }
    }
}

Prawidłowe typy

Fall-through

int n = 1;
 switch (n) {
  case 1:
  case 2:
   System.out.println("one or two");
  break;
}

Switch ze strzałkami

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

    String msg = switch (grade) {
      case "A" -> "Excellent";
      case "B", "C" -> "Passed";   
      default -> "Keep trying";
    };

    System.out.println(msg); 
  }
}

Demonstracja switch

public class Main {
  public static void main(String[] args) {
    // Instead of Scanner input, we assign a fixed value
    int day = 6;  // try changing this value (1–7)

    switch (day) {
      case 1:
      case 2:
      case 3:
      case 4:
      case 5:
        System.out.println("Weekday");
        break;
      case 6:
      case 7:
        System.out.println("Weekend");
        break;
      default:
        System.out.println("Invalid day");
    }
  }
}

Zapobieganie fall-through

Podsumowanie i następny krok