C# New features

I have move to .net 3.5 and found really cool enhancements in C# language(in VB.Net too).

• We can create properties like this
  

  class ProcessData
  {
  public int ID { get; set; }
  public string Name { get; set; }
  public long Memory { get; set; }
  }
  

  
  Compiler will emits the private variables for properties and nothing diffrent in IL code.
  
  
• Object Initializer
  Lets say we want to populate list of ProcessData class, before C# 3.0 came we have to code like this
  

  List processList = new List();
  foreach (Process p in Process.GetProcesses())
  {
  ProcessData pd = new ProcessData();
  pd.ID = p.Id;
  pd.Name = p.ProcessName;
  pd.Memory = p.WorkingSet64;
  processList.Add(pd);
  }

  
  Note its IL code,
  

  IL_001f: ldloc.2
  IL_0020: ldloc.1
  IL_0021: callvirt instance int32 [System]System.Diagnostics.Process::get_Id()
  IL_0026: callvirt instance void NewFeatures.ProcessData::set_ID(int32)
  IL_002b: nop
  IL_002c: ldloc.2
  IL_002d: ldloc.1
  IL_002e: callvirt instance string [System]System.Diagnostics.Process::get_ProcessName()
  IL_0033: callvirt instance void NewFeatures.ProcessData::set_Name(string)
  IL_0038: nop
  IL_0039: ldloc.2
  IL_003a: ldloc.1
  IL_003b: callvirt instance int64 [System]System.Diagnostics.Process::get_WorkingSet64()
  IL_0040: callvirt instance void NewFeatures.ProcessData::set_Memory(int64)
  IL_0045: nop
  IL_0046: ldloc.0
  IL_0047: ldloc.2
  IL_0048: callvirt instance void class [mscorlib]System.Collections.Generic.List`1::Add(!0)
  IL_004d: nop

  
  Do you belive if I write same code in 3 lines?
  

  var processList = new List();
  foreach (var p in Process.GetProcesses())
  processList.Add(new ProcessData { ID = p.Id, Name = p.ProcessName, Memory = p.WorkingSet64 });

  
  Note new ProcessData { ID = p.Id, Name = p.ProcessName, Memory = p.WorkingSet64 } is called object initializer notation.
  But it does same thing and no any drawbacks, like performance degrading etc. Check this IL code, it is same as above IL code.
  

    IL_001f:  ldloc.2
  IL_0020:  ldloc.1
  IL_0021:  callvirt   instance int32 [System]System.Diagnostics.Process::get_Id()
  IL_0026:  callvirt   instance void NewFeatures.ProcessData::set_ID(int32)
  IL_002b:  nop
  IL_002c:  ldloc.2
  IL_002d:  ldloc.1
  IL_002e:  callvirt   instance string [System]System.Diagnostics.Process::get_ProcessName()
  IL_0033:  callvirt   instance void NewFeatures.ProcessData::set_Name(string)
  IL_0038:  nop
  IL_0039:  ldloc.2
  IL_003a:  ldloc.1
  IL_003b:  callvirt   instance int64 [System]System.Diagnostics.Process::get_WorkingSet64()
  IL_0040:  callvirt   instance void NewFeatures.ProcessData::set_Memory(int64)
  IL_0045:  nop
  IL_0046:  ldloc.2
  IL_0047:  callvirt   instance void class [mscorlib]System.Collections.Generic.List`1::Add(!0)
  IL_004c:  nop

  
  We can see several advantages in the latter.
  + We can initialize an object within just one instruction.
  + We don’t need to provide a constructor to be able to initialize simple objects.
  + We don’t need several constructors to initialize different properties of objects.
  

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Reference: LINQ in Action, Manning Publications 2008