switch statement

1. 流程圖
   
   
   
   
2. 語法：break 可有可無，有沒有 break 有何差別？

   switch(expression){
       case constant-expression  :
          statement(s);
          break; /* optional */
       case constant-expression  :
          statement(s);
          break; /* optional */
     
       /* you can have any number of case statements */
       default : /* Optional */
          statement(s);
   }
   

3. 範例
   

   #include <stdio.h>
    
   int main ()
   {
      /* local variable definition */
      char grade = 'B';
   
      switch(grade)
      {
      case 'A' :
         printf("Excellent!\n" );
         break;
      case 'B' :
      case 'C' :
         printf("Well done\n" );
         break;
      case 'D' :
         printf("You passed\n" );
         break;
      case 'F' :
         printf("Better try again\n" );
         break;
      default :
         printf("Invalid grade\n" );
      }
      printf("Your grade is  %c\n", grade );
    
      return 0;
   }