C # 6.0 new features (reprint)

Brief introduction

The VS 2015 already contains C # 6.0. C # When publishing different versions, C # always has new features, such as dynamic features in linq,c#4.0 in c#3.0, asynchronous operations in c#5.0, and so on.

C # 6.0 adds a lot of new features to help developers better program.

The following example needs to download vs2015 so that there is a c#6.0 environment, the main new features are:

2. Use the static parameter to refer directly to a method or property in a class without having to take the class name each time.

   
   
   
   
   {     
     Class Program     
     {         
       static void Main (string[] args)         
       {            
         WriteLine ("This is the demo for C # 6.0 New Features");             
         ReadLine ();         
       }     
     }
   }
   

   
   
4. Member properties are automatically initialized, and when a property is defined, the value of the property can be initialized with simple code instead of being initialized in the constructor.

   public class Employee     
   {         
   Public Guid EmployeeId {get; set;} = Guid.NewGuid ();         
     public string FirstName {get; set;} = "Mukesh";         
     public string LastName {get; set;} = "Kumar";   
          
     public string FullName {get {return string. Format ("{0} {1}", FirstName, LastName); } }
   
   
   

6. The way the members are initialized in the collection changes to become more intuitive.

   Dictionary<int, string> mydictionary = new Dictionary<int, string> ()             
   {                 
     [1] = "Mukesh Kumar",                 
     [2] = "Rahul Rathor",                 
     [3] = "Yaduveer Saini",                 
     [4] = "Banke chamber"             
   

   
   
8. String formatting, used previously to use String.Format ("{0}-{1}", V1, V2); To format the output, use numbers, error-prone, and now use variable names directly

   Console.WriteLine ($"The full Name of Employee {FirstName} {lastName}");
   
   

10. In c#6.0, you can use a lambda expression to define a simple function within a line, rather than the traditional need to define a complete function.
    6.0 ago
    public static string Getfullname (String firstName, String lastName)         
    {             
       return string. Format ("{0} {1}", FirstName, LastName);         
    }
    6.0 in
    public static string Getfullname (String firstName, string lastName) = FirstName + "" + lastName;
    
    

12. Before c#6.0, a property needs to define both the get and set methods, even if the set method is not required at all, such as a read-only property. In c#6.0, you can define just one get method and set the initial value of the property

    String FirstName {get;} = "Mukesh";
    
    

14. exception handling improvements, in previous exception handling, you need to judge each outlier in a catch block, then execute different code, and in c#6.0, you can define multiple catch blocks to handle different code based on different outliers.

    try 
     {
     throw new Exception (errorcode.tostring ()); 
    } 
     catch (Exception ex)  when  (ex.             Message.equals ("404")) 
     {WriteLine ("This is Http Error"); 
     catch (Exception ex)  when  (ex.             Message.equals ("401")) 
     {WriteLine ("This is unathorized Error"); 
     catch (Exception ex) when (ex.             Message.equals ("403")) 
     {WriteLine ("Forbidden"); } 
     
     

16. Null value improvement, the previous operation of a variable needs to determine whether NULL, otherwise the program throws an exception; in c#6.0, you can use a simple question mark? Null is automatically determined, and if so, the null value is output.

    //            
    //            
    WriteLine (employees. FirstOrDefault ()?. Name);              
    
    //            
    WriteLine (employees. FirstOrDefault ()?. Name?? "My Value");

    
    
18. Variable declaration improvements, which previously declared a variable to return a value from a function, need to be defined outside the function, and in c#6.0, the variable can be defined directly in the function call.

    static void Main (string[] args)         
    {             
      if (int. TryParse ("+", out var result))             {                 
         return result;             
      }             
      return 0; Result is an out of scope
    }
    

    
    

Specific content and sample code can be consulted:

Http://www.codeproject.com/Articles/1070659/All-About-Csharp-New-Features

C # 6.0 new features (reprint)