How can I use goto in a switch statement in Objective-C?

Question

In my code I need to be able to jump (goto) a different case within the same switch statement. Is there a way to do this?

My code is something like this: (There is a lot of code I just left it all out)

switch (viewNumber) {
case 500:
        // [...]
break;

case 501:
        // [...]
break;
.
.
.
.
.

case 510:
        // [...]
break;

default:
break;

}

Thank you for your time! -Jeff

Answer 1

It's generally very bad practice to unconditionally jump like you're asking.

I think a more readable/maintainable solution would be to place the shared code in a method and have multiple cases call the method.

If you really want to, you can use goto to do something like:

switch(viewNumber) {
    case 500:
        // [...]
        goto jumpLabel;
    case 501:
        // [...]
        break;
    case 502:
        // [...]
        jumpLabel:
        // Code that 500 also will execute
        break;
    default:break;
}

Note: I only provided the code example above to answer your question. I now feel so dirty I might have to buy some Bad Code Offsets.

Answer 2

Instead of using goto, refactor your code so that the two (or more) cases that use common code instead call it in a common method.

Something like:

switch (value) {
   case (firstValue):
       // ...
       break;
   case (secondValue):
       [self doSharedCodeForSecondAndThirdValues];
       break;
   case (thirdValue):
       [self doSharedCodeForSecondAndThirdValues];
       break;
   default:
       break;
}

// ...

- (void) doSharedCodeForSecondAndThirdValues {
   // do stuff here that is common to second and third value cases
}

It wouldn't be the end of the world to use goto, though it is bad practice.

The practical reason for avoiding use of goto is that you have to search through your swtich-case tree to find that goto label.

If your switch logic changes, you'll have a messy situation on your hands.

If you pull out common code to its own method, the code is easier to read, debug and extend.