C switch statement with non-compound statement use case? [duplicate]

Question

It is possible to write a C switch statement with a non-compound sub-statement:

int x = 2;
int y = 3;

int main()
{
    switch (x)
        y++; // ok

    switch (x)
        case 2: y++; // ok
}

Is there any use case for this? That is, is there ever a reason to use a non-compound sub-statement of a switch statement?

Answer 1

The first switch block in the code doesn't do anything.

When switch statement expression is evaluated, the source code present until the occurrence of matching case label or default label, will be ignored. Hence it doesn't print statement "Before case" in the below program.

int x = 2;
int y = 3;

    int main()
    {
        switch (x)
        {
            y++; 
             printf("Before case");
         case 2:
            printf("In case 2");
            break;
         }

       return 0;
    }

Output:

In case 2

Answer 2

"Control passes to the statement whose case constant-expression matches the value of switch ( expression ). [...] Execution of the statement body begins at the selected statement and proceeds until the end of the body or until a break statement transfers control out of the body." (http://msdn.microsoft.com/)

I don't think the first switch does anything... When I compiled it, y was 4, which means it only incremented it once.