Why is the .ctor() created when I compile C# code into IL?

Question

With this simple C# code, I run csc hello.cs; ildasm /out=hello.txt hello.exe.

class Hello
{
    public static void Main()
    {
        System.         


        

Answer 1

A class for which you don't define a constructor gets an implicit public default constructor.

public MyClass()
  :base()
{
}

This only works if the base class has an accessible parameterless constructor.