New C# 6 functionality "Auto-Property initializers" is just a facilitator?

Question

One of the new C#6 features is the possibility to initialize properties at the time of declaration.

public class Customer
{
    public string First { get; set; } = "Jane";
    public string Last { get; set; } = "Doe";
}

The aim is only to facilitate the writing of the class, such as no longer needing to declare a constructor to perform the initializations, or behind something else?

Answer 1

The aim is only to facilitate the writing of the class, such as no longer needing to declare a constructor to perform the initializations, or behind something else?

Actually no longer need to declare constructores. Variable initialization was already done in a static context. Now the language opened the possibility to initialize properties as well.

Answer 2

Both the automatic properties available since C# 2 and their initialization available since version 6 are only syntactic sugars. It can even create the property more "manual" and initialize it in a constructor.

Of course, if you go deeper the property itself is just a couple of methods with specific characteristics, but let’s stick to this first layer of abstraction.

When you write

class Exemplo {
    public int valor { get; set; } = 1;
}

At heart it’s the same as

internal class Exemplo {
    private int valor;
    public int Valor {
        get { return valor; }
        set { valor = value; }
    }
    public Exemplo() {
        valor = 1;
    }
}

In fact the compiler generates code next to this:

.class private auto ansi beforefieldinit AutoPropertyInitializer.Exemplo
       extends [mscorlib]System.Object {
  .field private int32 '<Property>k__Valor'
  .custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
  .method public hidebysig specialname instance int32 
          get_Valor() cil managed {
              //corpo aqui
          }

  .method public hidebysig specialname instance void
          set_Valor(int32 'value') cil managed {
              //corpo aqui
          }

  .method public hidebysig specialname rtspecialname 
          instance void  .ctor() cil managed {
              // Code size       18 (0x12)
              .maxstack  8
              IL_0000:  ldarg.0
              IL_0001:  ldc.i4     0x1
              IL_0006:  stfld      int32 AutoPropertyInitializer.Exemplo::'<Property>k__Valor'
              IL_000b:  ldarg.0
              IL_000c:  call       instance void [mscorlib]System.Object::.ctor()
              IL_0011:  ret
          }

    .property instance int32 Valor() {
        .get instance int32 AutoPropertyInitializer.Exemplo::get_Valor()
        .set instance void AutoPropertyInitializer.Exemplo::set_Valor(int32)
    }
}

I put in the Github for future reference.