switch statement example

[Gaurav Gulanjkar]

public class Ebb{
static int x=7;
public static void main(String args[]){
String s=" ";
for(int y=0;y<3;y++){
x++;
             switch(x){
              case 8: s+="8";
              case 9: s+="9";
              case 10: {s+="10"; break;}
              default: s+="d";
              case 13: s+="13";
                             }
          }
          System.out.println(s);
}
static{x++;}
}

unable to figure out the output of the preceding code from k&b book page no-415.

[Peter Swiss]

Class Ebb is loaded - static variable x is initialized to 7. static intializer block runs , x is incremented to 8
main method begins:
for loop:
1st iteration: x becomes 9, switch goes to case 9, prints 9, fall-thru to 10, prints 10 and break
2nd iteration: x becomes 10, switch goes to case 10, prints 10 and break
3rd iteration: x becomes 11, switch goes to default, prints d, fall-thru to 13, prints 13

You get "9 10 10 d 13"

Option D is correct



Peter Swiss

[Seetharaman Venkatasamy]

notable point here is that the break inside switch dont interrupt the for loop; only break outside the switch has effect on for loop.

[Gaurav Gulanjkar]

but how is x incremented to 9 as the operator used is post increment operator and it says that first use and then increment at first iteration.

[Peter Swiss]

Gaurav Gulanjkar wrote: it says that first use and then increment at first iteration.

the statement is x++;

you use x then increment. The scope of "use" is only for the current statement.
So you use it - it is 8
you increment it - it is 9

[Gaurav Gulanjkar]

I got it.
thank you to all of you for clearing my doubt's.