switch语句允许根据值判断是否相等性，每个值称为一个case语句，并且为每个switch case检查每个变量。

switch - 语法

D编程语言中switch语句语法如下所示:-

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); 
}

switch - 流程图

switch - 示例

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

编译并执行上述代码时，将生成以下结果-

Well done 
Your grade is B