scope.c

  int main()
     {
        {
            int x = 10, y  = 20;
             {
                 // The outer block contains declaration of x and y, so 
               // following statement is valid and prints 10 and 20
               printf("x = %d, y = %d\n", x, y);
                  {
                      // y is declared again, so outer block y is not accessible 
                      // in this block
                      int y = 40;
            
                      x++;  // Changes the outer block variable x to 11
                      y++;  // Changes this block's variable y to 41
              
                      printf("x = %d, y = %d\n", x, y);
                  }
          // This statement accesses only outer block's variables
                 printf("x = %d, y = %d\n", x, y);
             }
        }
        return 0;
     }