switch case 为何不允许嵌套? 如何实现我需要的功能? 只能用else if 吗?

Question

           switch( type)
           {
               case 0x00:
                   return "ICMP_ECHOREPLY";
                   break;
               case 0x03:
                   switch (subCode)
                   {
                       case 0x00:
                           return "ICMP_UNREACH_NET";
                           break;
                          ................//省略若干
                       default:
                           return "TYPE0X03 未知数据包";
                           break;
                   }
                   break;
              ...................//省略若干
               default:
                   return "unknowPacket";
                   break;
           }

Answer 1

我做的测试，是可以的。具体的代码如下：
 protected void Page_Load(object sender, EventArgs e)
    {
        int m = 12;
        int n = 12;
        switch (m)
        {   
            case 1:
                break;
            case 12:
                switch (n)
                {
                    case 12:
                        Response.Write("Ok");
                        break;
                    default:
                        break;
                }
                break;
            default:
                break;
        }
        
    }

Answer 2

我试过。可以的。另外你的代码中return后又break,没有意义的。

Answer 3

你嵌套的里面用return不对,你里面又用了return,你让程序帮你返回到什么地方去

Answer 4

switch嵌套使用也是没问题的。你把你的出错提示贴出来，这样才能找问题原因，不要自己先”确诊“再让别人给你找原因。switch (flag)
            {
                case 0:
                    return 10;
                case 1:
                    switch (type)
                    {
                        case 0:
                            return 100;
                        case 1: 
                            return 200;
                        default:
                            return 30;
                    }
                default:
                    return 30;
            }

Answer 5

9楼的代码 测试通过 VS2005switch   (flag) 
                        { 
                                case   0: 
                                        return   10; 
                                case   1: 
                                        switch   (type) 
                                        { 
                                                case   0: 
                                                        return   100; 
                                                case   1:   
                                                        return   200; 
                                                default: 
                                                        return   30; 
                                        } 
                                default: 
                                        return   30; 
                        }

Answer 6

都return了，break当然没意义了

Answer 7

return了又break当然会出错了！

Answer 8

return了又break会给处警告信息但不会影响程序的运行。这不算错。但是有return就不要写break；或有break就不要写return！

Answer 9

非也非也，编译器不认为你错并不代表程序没错，return了又break对于程序员来说就是个错！

Answer 10

呵呵，break和return,都是跳出程序执行块楼主，好好理解哈switch case语句执行块，应该很简单的哦！

Answer 11

switch可以嵌套，是你的代码有问题。

Answer 12

switch可以嵌套的。上面已经讲了