break
语句用于终止最近的封闭循环或它所在的switch语句。控制传递给终止语句后面的语句（如果有的话）。
/// <summary>/// break 示例/// 在此例中，条件语句包含一个应该从1计数到100的计数器/// 但break语句在计数达到4后终止循环。/// </summary>static void Main(){for (int i = 1; i <= 100; i++){if (i == 5){break;}Console.WriteLine(i);}}
continue
语句将控制权传递给它所在的封闭迭代语句的下一次迭代。
/// <summary>/// continue 示例/// 在此示例中，计数器最初是从 1 到 10 进行计数 // 但通过将 continue 语句与表达式 (i< 9) 一起使用/// 跳过了 continue 与 for 循环体末尾之间的语句。/// </summary>static void Main(){for (int i = 1; i <= 10; i++){if (i < 9){continue;}Console.WriteLine(i);}}
goto
语句将程序控制直接传递给标记语句。goto的一个通常用法是将控制传递给特定的switch-case标签或switch语句中的默认标签。goto语句还用于跳出深嵌套循环。
/// <summary>/// goto 示例/// 输入 2 /// 示例输出/// Coffee sizes: 1=Small 2=Medium 3=Large/// Please enter your selection: 2 /// Please insert 50 cents. /// Thank you for your business./// </summary>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.");}
/// <summary>/// goto 示例2/// 下面的示例演示了使用 goto 跳出嵌套循环/// 输入44示例输出/// Enterthenumbertosearchfor:44/// The number 44 is found./// End of search./// </summary>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."); }
return
语句终止它出现在其中的方法的执行并将控制返回给调用方法。它还可以返回一个可选值。如果方法为void类型，则可以省略return语句。
throw
语句用于发出在程序执行期间出现反常情况（异常）的信号。通常throw语句与try-catch或try-finally语句一起使用。当引发异常时，程序查找处理此异常的catch语句。也可以用
throw语句重新引发已捕获的异常。
/// <summary>/// thow 示例/// </summary>static void Main(){string s = null;if (s == null){throw new ArgumentNullException();}Console.Write("The string s is null");// not executed }
