What's new in C# 6

Roslyn open source

  IDE Features (CTL+.)
  . lightball to remove unused namespace
    .. fix the scope , remove all unused cross the project / solutions
  . refactor
    rename, introduce local variable, show conflict
    add this automaticaly if their is conflict that could be resolved by IDE
  . Array vs ImmutableArray

  var c=new ImmutableArray(); call c.length will trigger null exception.
  //you can build code analyzer
  //tell the ide you shoudl you  ImmutableArray<int>.empty

language new features
  instead of big change, little things added.

  1.using static System.Console. //simar typescript import {WriteLine} from systemcnosole

    then you can call WriteLine methods.
  2.Immutable, auto property.
    public class Point
    {
      public int x {get;}
      public int y {get;}=default10;
    }
  3 lambda for methods
    public void string ToString()=>String.format("tostring {0}", x);

  4 $String,
    public void String toString()=>$({X}{Y})
  5. nameof(variable)
    Log.d(nameof(variable))
  6.?.
    if p!=null && p.name=="xxx"
    will be if p?.name=="xx"
    if json!=null && json['x']!=null && json['x']=="mon"
    will be
    if(json?['x']?=="mon")
  7.initlize elements
    public JObject tojson()=>return new jsonobject(){['x']=x, ['Y']=y }
  8. awit in catch block

    try
    {
    var result=await repo.DosomethingAsync();
    }
    catch(Excepton ex)
    {
      await repo.LogException(ex) //doable now
    }

  9.catch(Exception ex) when (ex.Occurences>3)


Debugging features
  1. you can edit code, even add new class , and do initialization code when debugging the app
    run linq query

    also in watch window
    people.find(p=>p.age>20)

  C# extensions toolkit in the extnsion gallery
  2. C# interactive window

      #r "System"
      #r "System.Core"
      using System.Diagnostics;
      using System.linq;
      var memoryPigs =from p in Process.getProcesses() where p.workset64 >64*1024*1024 select new
      {p.ProcessName, p.WorkingSet}
      foreach(var r in memopigs)
      {
      Console.writeline(r)7y
      }