Question

Possible Duplicate:
Code before the first ‘case’ in a switch-statement

I have the following set of code in C:

void isFindValue(int value1, int value2)
{
    switch (value1)
    {
    case 1:
      printf("value1 is found!\n");
      break;

    case 2:
      printf("value1 is found!\n");
      break;

    case 3:
      switch(value2)
      {
    printf("aaaaaaaaaaaaa\n");
     case 6:
         printf("bbbbbbbbbbbb\n");
         printf("value2 is found!\n");
         break;
      }
     default:
     break;    
}

if I call the function as is isFindValue(3,6); the printf of bbbbbbbbbbbb show up, but aaaaaaaaaaaaa does not, why this will happen? should we not do something before the case?

Answer 1

Because switch () works using labels. It jumps to the label of which the condition is satisfied. So when reaching

switch(value2) {
    printf("aaaaaaaaaaaaa\n");
    case 6:

the control flow immediately jumps to the label case 6: so that it skips the call to printf().

The solution would be placing it correctly, outside of the inner switch:

case 3:
    printf("aaaaa\n");
    switch (value2) {

etc.