C语言嵌套的switch语句

#include <stdio.h>

int main () {

   /* local variable deFinition */
   int a = 100;
   int b = 200;

   switch(a) {

      case 100: 
         printf("This is part of outer switch\n", a );

         switch(b) {
            case 200:
               printf("This is part of inner switch\n", a );
         }
   }

   printf("Exact value of a is : %d\n", a );
   printf("Exact value of b is : %d\n", b );

   return 0;
}