D语言嵌套switch语句

发布于 2015-08-16 14:55:11 | 186 次阅读 | 评论: 0 | 来源: 网络整理

一个switch可以作为外部switch的语句序列的一部分。即使内部和外部switch的case，常含有共同的值，冲突也不会产生。

语法

嵌套switch语句的语法如下：

switch(ch1) {
   case 'A': 
      writefln("This A is part of outer switch" );
      switch(ch2) {
         case 'A':
            writefln("This A is part of inner switch" );
            break;
         case 'B': /* case code */
      }
      break;
   case 'B': /* case code */
}

例子：

import std.stdio;

int main ()
{
   /* local variable definition */
   int a = 100;
   int b = 200;

   switch(a) {
      case 100:
         writefln("This is part of outer switch", a );
         switch(b) {
            case 200:
               writefln("This is part of inner switch", a );
               default:
                    break;
         }
       default:
          break;
   }
   writefln("Exact value of a is : %d", a );
   writefln("Exact value of b is : %d", b );
 
   return 0;
}

让我们编译和运行上面的程序，这将产生以下结果：

This is part of outer switch
This is part of inner switch
Exact value of a is : 100
Exact value of b is : 200