Thread: switch - continue

In my CS course a couple semesters ago at college, my professor stated that you can make a very clever iterative construct using switch and continue statements. He stated that when a continue statement was placed inside of a switch construct, and that continue statement was executed, it would go back up to the top of the switch statement and re-evaluate the switch.

This intrigued me, as I have been programming in C/C++ for almost 6 years now and have never thought of doing such a thing, or seen anyone else something like that.

But I thought it would be pretty cool to make an iterative switch statement using continue statements instead of break statements, so I decided to try it out. Unfortunatley it doesnt seem to work. So far I have tried it on gcc, g++, and Turbo C++ and none of them like it.

Should I email my professor and tell him he was utterly wrong?

>Should I email my professor and tell him he was utterly wrong?
Yes. continue can only appear in a loop body. Your professor either has no idea what he's talking about, or is relying on a nonstandard extension.

On second thought, you may have misunderstood him. If the switch is contained in a loop and you use continue, the next iteration of the loop will be executed and the switch condition re-evaluated. That could be what he meant. For example, this prints only the odd numbers:

Code:

for (i = 0; i < 10; i++) {
  switch (i % 2) {
    case 0:
      continue;
    default:
      printf("%d\n", i);
      break;
  }
}

Originally Posted by Prelude

>Should I email my professor and tell him he was utterly wrong?
Yes. continue can only appear in a loop body. Your professor either has no idea what he's talking about, or is relying on a nonstandard extension.

On second thought, you may have misunderstood him. If the switch is contained in a loop and you use continue, the next iteration of the loop will be executed and the switch condition re-evaluated. That could be what he meant. For example, this prints only the odd numbers:

Code:

for (i = 0; i < 10; i++) {
  switch (i % 2) {
    case 0:
      continue;
    default:
      printf("%d\n", i);
      break;
  }
}

do does

Code:

for (i = 0; i < 10; i++) {
  switch (i % 2) {
    case 0:
      break;
    default:
      printf("%d\n", i);
      break;
  }
}

I doubt that would be what he ment - unless this is just a very vague example where it's rediculous to mention continue instead of break.