Unable to get behaviour of Switch case in java

Question

I have written small code in java 6

public class TestSwitch{

public static void main(String... args){
    int a = 1;
    System.out.println("start");
          


        

Answer 1

 See if a=1 then your case 1 will work then 1 will pe printed if as we have not using      break after case 1 so all cases are working in flow so output is coming like this if you want to execute only one case at one time then you have to put break after one case like

switch(a){
        case 1:
            System.out.println(1);
             break;
            case 3:
                System.out.println(3);
             break;
            case 4:
                System.out.println(4);
             break;

Then it will break out of the switch case on encountering break statement

Answer 2

Your code will give compilation errors as we can't use curly brace after case : Exact code is:

public static void main(String... args){
        int a = 1;
        System.out.println("start");
        switch(a){
            case 1:
                System.out.println(1);
                case 3:
                    System.out.println(3);
                case 4:
                    System.out.println(4);

            case 2:
                System.out.println(2);
                case 5:
                    System.out.println(5);
                case 7:
                    System.out.println(7);
            }

        System.out.println("end");
    }
    }

and output will be start 1 3 4 2 5 7 end because you have not use "break" after each case.