What does comma operator mean in a switch statement?

Question

I was given a question and was asked to give the output.

int main(void){  
    int x = 2;  
    switch(x){  
        case 1,2,1: printf(\"Case 1 is executed\         


        

Answer 1

FYI, today one may use the GCC case ranges extension when it is appropriate (which is not often) for similar results (only ranges are supported, not arbitrary lists of values).

case 1 ... 5:
case 'A' ... 'Z':