Program.cs

namespace Construction;

class Program
{
    // This example runs constructors for their side effects, so warning
    // CA1806 (which tells us we've constructed an object but not used it)
    // is unhelpful here.
#pragma warning disable CA1806
    static void Main()
    {
        new Example37.DerivedNoDefaultCtor(42);

        Console.WriteLine();

        new Example38.DerivedCallingBaseCtor();

        Console.WriteLine();

        new DerivedInit();
    }
}

public class BaseInit
{
    protected static int Init(string message)
    {
        Console.WriteLine(message);
        return 1;
    }

    private int b1 = Init("Base field b1");

    public BaseInit()
    {
        Init("Base constructor");
    }

    private int b2 = Init("Base field b2");
}

public class DerivedInit : BaseInit
{
    private int d1 = Init("Derived field d1");

    public DerivedInit()
    {
        Init("Derived constructor");
    }

    private int d2 = Init("Derived field d2");
}