C#6.0语法糖

  1 using System;
  2 using static System.Math;//using static,仅仅引入类中的静态方法
  3 namespace _6._0Syntax
  4 {
  5     class Program
  6     {
  7          delegate bool Predicate(string str);
  8         static void Main(string[] args)
  9         {
 10             /*nameof 
 11              string a = nameof(Program.Main);
 12             */
 13 
 14             /*String interpolation
 15               var s = string.Format("{0} is so beauty{{~~~}}", "You");
 16             Person p = new Person { Name = "senki", Age = 12 };
 17             var s = $"{p.Name,20} is {p.Age:D3} year{{s}} old";
 18             */
 19 
 20             /*NULL操作            
 21             string str = null;
 22             int? length = str?.Length;
 23             char? c = str?[0];
 24             int l = str?.Length ?? 0;
 25             List<Person> list = null;
 26             int? b= list?[0]?.Name?.Length;
 27             Predicate predicate = null;
 28             if (predicate?.Invoke(str) ?? false)
 29             {
 30             }
 31             */
 32 
 33             /*初始化时设定索引
 34               var numbers = new Dictionary<int, string> {
 35                  [7]="liu",
 36                  [9]="zhan",
 37                  [15]="qi"
 38              };*/
 39 
 40             /* 异常过滤器
 41              try
 42              {
 43                  throw new CustomException();
 44              }
 45              catch (Exception e) when (IsCanCatch(e))
 46              {                 
 47              }
 48              */
 49             Max(1, 2);//通过using static,直接使用静态方法
 50             Console.WriteLine(1);
 51             Console.ReadLine();
 52         }
 53 
 54         //表达式函数
 55         static void Print(string str) => Console.WriteLine($"{str}");
 56 
 57         class Person 
 58         {
 59             public string Name { get; set; } = "senki";//自动属性初始值设定
 60             public bool Sex { get; } = true;
 61             public int Age { get; set; }
 62             public string LastName => Name;//只读属性
 63             public char this[int i]=>Name?[i]??'A';//索引
 64            
 65 
 66         }
 67         class CustomException : Exception
 68         {
 69             public override string Message
 70             {
 71                 get
 72                 {
 73                     return "测试异常";
 74                 }
 75             }
 76         }
 77         private static bool IsCanCatch(Exception e)
 78         {
 79             if (e is CustomException)
 80                 return true;
 81             return false;
 82         }
 83 
 84         struct School
 85         {
 86             public string Name { get; set; }
 87             public int Age { get; }
 88             public School(string name, int age)
 89             {
 90                 Name = name;
 91                 Age = age;
 92             }
 93             //public School():this("",120)
 94             //{ }
 95 
 96         }
 97 
 98          
 99 }
100 }