continue statement example

[Rajiv Goyal]

see the code:

public class Rainbow {
2. public static void main(String[] args) {
3. int count = 0;
4. String[] colours = {"red", "orange", "yellow", "green",
5. "blue", "indigo", "violet"};
6. start: for (int i = 0; i < 5; i++) {
7. switch (i) {
8. case 0:
9. count--;
10. break;
11. case 3:
12. continue start;
13. case 4:
14. count--;
15. break start;
16. default:
17. count++;
18. break;
19. } // switch end
20. count++;
21. }
22. System.out.println(colours[count]);
23. }
24.}





1 Standard output will display 'red'.
2 Standard output will display 'green'.
3 Standard output will display 'indigo'.
4 Standard output will display 'violet'.
5 An ArrayIndexOutOfBoundsException will be thrown, halting the program

Answer is green(2)
-Lost somewhere in making out flow in continue statement.
Can someway explain the flow clearly with values in each iterations?
thanks,
rajiv

[Arun Subbu]

Hi,
This is the flow. hope this helps
count = 0;
i = 0 count = -1;
count = 0 (Outside the switch)
i =1 count = 1;
count = 2(Outside the switch)
i =2 count = 3;
count =4 (Outside the switch)
i =3 ,tries to transfer the control to start of the loop,since there is no break,the code
falls to case i =4
count =3,now the break start breaks the for loop itself.
so colours[count] evalutes to colours[3] which is green.

[Arun Subbu]

Hi Rajiv,
sorry about the previous post. i misunderstood the code. this is right execution sequence.
count = 0;
i = 0 count = -1;
count = 0 (Outside the switch)
i =1 count = 1;
count = 2(Outside the switch)
i =2 count = 3;
count =4 (Outside the switch)
i =3 ,transfers the control to start of the loop,
I = 4 count = 3;
break start breaks the for loop.
so colours[count] evalutes to colours[3] which is green.

[Vicken Karaoghlanian]

public class Rainbow {
public static void main(String[] args) {
int count = 0;
String[] colours = {"red", "orange", "yellow", "green","blue", "indigo", "violet"};

start: 
for (int i = 0; i < 5; i++) {
switch (i) {
case 0:
count--;
break;
case 3:
continue start;
case 4:
count--;
break start;
default:
count++;
break;
}

count++; // here
}

System.out.println(colours[count]);
}
}

Rajiv> make your code more clear by using UBB code, it'll allow more people to help you.
Arun> the break statement in the switch clause doesn't break the loop, it only breaks the switch statement... i see you've missed the count++ after the switch.
here are the correct values for each iteration:
itr 1)i = 0
count = 0 -1 0
itr 2)i = 1
count = 0 1 2
itr 3)i = 2
count = 2 3 4
itr 4)i = 3
count = 4 // no vars are changes here except for i
itr 5)i = 4
count = 4 3 // the for loop breaks
as you can see final count value is 3, therfore printing green.
[ September 04, 2003: Message edited by: Vicken Karaoghlanian ]
[ September 04, 2003: Message edited by: Vicken Karaoghlanian ]

[Rajiv Goyal]

vicken,Arun
thanks for your great effort,
rajiv

[Arun Subbu]

Hi Vicken,
I believe you are wrong. break start will break the loop for sure.i am debugging the code. change break start to break,now count will become 4 and then it will go to the begining of the loop,the conition fails and it will print blue colours[4] = blue.
correct me if i am wrong.

[Vicken Karaoghlanian]

hi arun,
i was refering to break NOT break start
break will get you out of the switch, increment count (count++), then precede to the next iteration of the loop.
break start will get you out of the switch stat. AND also the for loop, in this case count is not incremented (count++).
in your first iteration of the the loop count becomes 0 not -1, because the break stat. in case0 will break the switch then it'll procede down to count++ and then finally incrementing the index i.
i beleive my output is correct, if you don't think so please explain why.
[ September 04, 2003: Message edited by: Vicken Karaoghlanian ]

[Vicken Karaoghlanian]

Arun... i don't no why are we arguing about!!! the code you posted is the same as mine... the only problem is that i've just noticed that i misread your output.
i believe we are both correct.