7.0 New Features C # Demo

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Text;
  4 using static System.Console;
  5 
  6 namespace ConsoleApp1
  7 {
  8     public class CSharp7
  9     {
 10         public static int b = 0b0001;
 11         public static int b2 = 0b0001_00_00;
 12         public static long salary = 1000_000_000;
 13         public  static  decimal PI = . 3 .141_592_653_589m;
 14  
15  
16          Private  int _age;    
 . 17          public   int Age
 18 is          {
 . 19              GET => _age;
 20 is              /// C # statement disposable throw statement 
21 is              SET => = _age value <= 0 || value> = 130. ? the throw  new new ArgumentException The ( " invalid parameters " ): value;
 22 is          } 
 23 is  
24          public  String Name { get; set; } = "jefft";
 25 
 26         /// <summary>
 27         /// 解构方法
 28         /// </summary>
 29         /// <param name="name"></param>
 30         /// <param name="age"></param>
 31         public void Deconstruct(out string name, out int age)
 32         {
 33             name = Name;
 34             age = Age;
 35         }
 36  
37 [          public CSharp7 ()
 38 is          {
 39  
40          }
 41 is  
42 is  
43 is          // local function 
44 is          public  static  void Outer ()
 45          {
 46 is              the WriteLine ( " local approach: " );
 47              Inner ( . 5 );
 48              Inner ( 10 );
 49              Inner ( 12 is );
 50  
51 is             void Inner ( int len =10)
 52             {             
 53                for(var i = 0; i< len; i++)
 54                 {
 55                     Write($" {i},");
 56                 }
 57 
 58                 WriteLine();
 59             }
 60         }
 61 
 62          ~CSharp7() => Console.WriteLine("Finalized!");
 63 
 64 
 65         public static void Instance()
 66         {
 67             var item = new CSharp7();
 68             item.Age = 30;
 69             var (name, age) = item;
 70             WriteLine($"解构结果:name:{name},age: {age}");             
 71         }
 72 
 73         public static void TestNumberForamt()
 74         {
 75             WriteLine($"pi={pi}, salary={salary}, b={b}, b2={b2}");
 76         }
77  
78          public  static  void TestOutTypeVar ()
 79          {
 80              the WriteLine ( " Enter a number: " );
 81              var INPUT = the ReadLine ();
 82              IF ( int .TryParse (INPUT, OUT  var Result))
 83              {
 84                  the WriteLine ( " Your digital input is: {0} " , Result);
 85              }
 86              the else 
87              {
 88                  the WriteLine (" Unable to parse input ... " );
 89              }
 90          }
 91 is  
92          public  static  void TestTuple ()
 93          {
 94              the WriteLine ( " Tuple :: " );
 95  
96              /// Default 
97              var tuple = ( 12 is , 23 is );
 98              the WriteLine ($ " {} tuple.Item1, tuple.Item2 {} " );
 99  
100              /// left => deconstruction 
101              var (One, TWO) = (11, 22);
102             WriteLine($"{one},{two}");
103 
104             ///右边
105             var tuple2= (one: 1, two: 2);
106             WriteLine($"{tuple2.one},{tuple2.two}");
107         }
108              
109         public static void TestLoaclRef()
110         {
111             int[,] arr = { { 11, 15 }, { 22, 25 } };         
112 
113             ref var num = ref GetLocalRef(arr, c => c % 2 == 0);
114             Console.WriteLine($"原数值{arr[1, 0]}");
115             num = 600;
116             Console.WriteLine($"新数值{arr[1, 0]}");
117           
118         }
119 
120         static ref int GetLocalRef(int[,] arr, Func<int, bool> func)
121         {
122             for (int i = 0; i < arr.GetLength(0); i++)
123             {
124                 for (int j = 0; j < arr.GetLength(1); j++)
125                 {
126                     if (func(arr[i, j]))
127                     {
128                         return ref arr[i, j];
129                     }
130                 }
131             }
132 
133             throw new InvalidOperationException("Not found");
134         }
135 
136 
137         public static void TestCaseTypeVar(object item)
138         { 
139             switch(item)
140             {
141                 case int i when i< 10:
142                     WriteLine($"int类型:{i},且数字小于10");
143                     break;
144                 case int i:
145                      the WriteLine ($ " int type: {i}, and is a number greater than equal to 10 " );
 146                      BREAK ;
 147                  Case  a float F:
 148                      the WriteLine ($ " floating-point type: {F} " );
 149                      BREAK ;
 150                  Case  String STR When int .TryParse (STR, OUT  int Result):
 151                      the WriteLine ($ " character string type int Switch type: Result {} " );
 152                      BREAK ;
 153                  default :
 154                     BREAK ;
 155              }
 156          }
 157  
158          public  static  void TestIsTypeVar ( Object Item)
 159          {
 160.              IF (Item IS  int I && I < 10 )
 161              {
 162                  the WriteLine ($ " int type: {i}, and the number is smaller than 10 " ) ;
 163              }
 164 is              the else  IF (Item IS  int I2)
 165              {
 166                 The WriteLine ($ " int type: {i2}, and is a number greater than equal to 10 " );
 167 is              }
 168              the else  IF (Item IS  a float F)
 169              {
 170.                  the WriteLine ($ " floating-point type: {F} " );
 171 is              }
 172              the else  IF (Item IS  string STR && int .TryParse (STR, OUT  int Result))
 173              {
 174                  the WriteLine ($ " character string type int Switch type: {result}");
175             }
176         }
177     }
178 }

 1   static void Csharp7Test()
 2         {
 3             CSharp7.TestIsTypeVar("77");
 4             CSharp7.TestCaseTypeVar("88");
 5          
 6             CSharp7.TestNumberForamt();
 7             CSharp7.Outer();
 8             CSharp7.Instance();
 9             CSharp7.TestTuple();           
10             CSharp7.TestLoaclRef();
11             CSharp7.TestOutTypeVar();
12             Console.ReadKey();
13         }