goto命令不起作用

Question

當我在沒有goto命令的情況下執行代碼時，它可以工作，但是當我添加:Start時，它會得到一個8錯誤。

下面是相關代碼：

 :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

正確的語法是Start:。但是，不是goto，你應該在一個循環中進行設置：

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

試試 「開始：」 而不是 「：啓動」 這樣的：

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

一個標籤的正確的語法是Start:，不:Start

您可以重構代碼省略goto語句代替（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; 
    } 
}