重拾C#日常積累:goto特殊的跳轉語句
阿新 • • 發佈:2019-01-27
goto跳轉語句說明
- goto語句將程式控制直接傳遞給標記語句。
- goto的一個通常用法是將控制傳遞給特定的 switch-case 標籤或switch語句中的預設標籤。
- goto語句還用於跳出深巢狀迴圈。
示例程式
1、在switch當中
class SwitchTest { static void Main() { Console.WriteLine("Coffee sizes: 1=Small 2=Medium 3=Large"); Console.Write("Please enter your selection: "); string s = Console.ReadLine(); int n = int.Parse(s); int cost = 0; switch (n) { case 1: cost += 25; break; case 2: cost += 25; goto case 1; case 3: cost += 50; goto case 1; default: Console.WriteLine("Invalid selection."); break; } if (cost != 0) { Console.WriteLine("Please insert {0} cents.", cost); } Console.WriteLine("Thank you for your business."); // Keep the console open in debug mode. Console.WriteLine("Press any key to exit."); Console.ReadKey(); } } /* Sample Input: 2 Sample Output: Coffee sizes: 1=Small 2=Medium 3=Large Please enter your selection: 2 Please insert 50 cents. Thank you for your business. */
2、goto跳出迴圈
參考地址:https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/gotopublic class GotoTest1 { static void Main() { int x = 200, y = 4; int count = 0; string[,] array = new string[x, y]; // Initialize the array: for (int i = 0; i < x; i++) for (int j = 0; j < y; j++) array[i, j] = (++count).ToString(); // Read input: Console.Write("Enter the number to search for: "); // Input a string: string myNumber = Console.ReadLine(); // Search: for (int i = 0; i < x; i++) { for (int j = 0; j < y; j++) { if (array[i, j].Equals(myNumber)) { goto Found; } } } Console.WriteLine("The number {0} was not found.", myNumber); goto Finish; Found: Console.WriteLine("The number {0} is found.", myNumber); Finish: Console.WriteLine("End of search."); // Keep the console open in debug mode. Console.WriteLine("Press any key to exit."); Console.ReadKey(); } } /* Sample Input: 44 Sample Output Enter the number to search for: 44 The number 44 is found. End of search. */