C# 语句大全!

C# 中的大多数语句都是直接从 C 和 C++ 借用的，但有一些值得注意的添加和修改。下表列出了可用的语句类型，并提供了每种类型的示例。 语句列表和块语句  static void Main() {     F();     G();     {         H();         I();     } }   标记语句和 goto 语句  static void Main(string[] args) {     if (args.Length == 0)         goto done;     Console.WriteLine(args.Length); done:     Console.WriteLine("Done"); }   局部常数声明  static void Main() {     const float pi = 3.14f;     const int r = 123;     Console.WriteLine(pi * r * r); }   局部变量声明  static void Main() {     int a;     int b = 2, c = 3;     a = 1;     Console.WriteLine(a + b + c); }   表达式语句  static int F(int a, int b) {     return a + b; } static void Main() {     F(1, 2);  // Expression statement }   if 语句  static void Main(string[] args) {     if (args.Length == 0)         Console.WriteLine("No args");     else         Console.WriteLine("Args"); }   switch 语句  static void Main(string[] args) {     switch (args.Length) {         case 0:             Console.WriteLine("No args");             break;         case 1:             Console.WriteLine("One arg ");             break;         default:             int n = args.Length;             Console.WriteLine("{0} args", n);             break;     } }   while 语句  static void Main(string[] args) {     int i = 0;     while (i < args.Length) {         Console.WriteLine(args[i]);         i++;     } }   do 语句  static void Main() {     string s;     do { s = Console.ReadLine(); }     while (s != "Exit"); }   for 语句  static void Main(string[] args) {     for (int i = 0; i < args.Length; i++)         Console.WriteLine(args[i]); }   foreach 语句  static void Main(string[] args) {     foreach (string s in args)         Console.WriteLine(s); }   break 语句  static void Main(string[] args) {     int i = 0;     while (true) {         if (i == args.Length)             break;         Console.WriteLine(args[i++]);     } }   continue 语句  static void Main(string[] args) {     int i = 0;     while (true) {        Console.WriteLine(args[i++]);        if (i < args.Length)             continue;        break;     } }   return 语句  static int F(int a, int b) {     return a + b; } static void Main() {     Console.WriteLine(F(1, 2));     return; }   throw 语句和 try 语句  static int F(int a, int b) {     if (b == 0)         throw new Exception("Divide by zero");     return a / b; } static void Main() {     try {         Console.WriteLine(F(5, 0));     }     catch(Exception e) {         Console.WriteLine("Error");     } }   checked 和 unchecked 语句  static void Main() {     int x = Int32.MaxValue;     Console.WriteLine(x + 1);      // Overflow     checked {         Console.WriteLine(x + 1);  // Exception     }         unchecked {         Console.WriteLine(x + 1);  // Overflow     } }   lock 语句  static void Main() {     A a = ...;     lock(a) {         a.P = a.P + 1;     } }   using statements  static void Main() {     using (Resource r = new Resource()) {         r.F();     } }