goto命令不起作用

Question

当我在没有goto命令的情况下执行代码时，它可以工作，但是当我添加:Start时，它会得到一个8错误。

下面是相关代码：

 :Start 
     Console.Write("Do you want the yes or no?"); 
     string what = Console.ReadLine(); 
     switch (what) 
     { 
      case "yes": 
       Console.WriteLine("You choose yes"); 
       break; 
      case "no": 
       Console.WriteLine("You choose no"); 
       break; 
      default: 
       Console.WriteLine("{0},is not a word",what); 
       goto Start; 
     } 

Answer 1

正确的语法是Start:。但是，不是goto，你应该在一个循环中进行设置：

bool invalid = true; 
while (invalid) 
{ 
    Console.Write("Do you want the yes or no?"); 
    string what = Console.ReadLine(); 
    switch (what) 
    { 
     case "yes": 
      Console.WriteLine("You choose yes"); 
      invalid = false; 
      break; 
     case "no": 
      Console.WriteLine("You choose no"); 
      invalid = false; 
      break; 
     default: 
      Console.WriteLine("{0},is not a word",what); 
    } 
} 

Answer 2

试试 “开始：” 而不是 “：启动” 这样的：

Start: 
      Console.Write("Do you want the yes or no?"); 
      string what = Console.ReadLine(); 
      switch (what) 
      { 
       case "yes": 
        Console.WriteLine("You choose yes"); 
        break; 
       case "no": 
        Console.WriteLine("You choose no"); 
        break; 
       default: 
        Console.WriteLine("{0},is not a word", what); 
        goto Start; 
      } 

http://msdn.microsoft.com/en-us/library/aa664740(v=vs.71).aspx

Answer 3

一个标签的正确的语法是Start:，不:Start

您可以重构代码省略goto语句代替（better ）：

bool continue = true; 
while (continue) { 
    Console.Write("Do you want the yes or no?"); 
    string what = Console.ReadLine(); 
    switch (what) 
    { 
     case "yes": 
      Console.WriteLine("You choose yes"); 
      continue = false; 
      break; 
     case "no": 
      Console.WriteLine("You choose no"); 
      continue = false; 
      break; 
     default: 
      Console.WriteLine("{0}, is not a word",what); 
      break; 
    } 
}