Why is it necessary for a base class to have a constructor that takes 0 args?

Question

This won\'t compile:

namespace Constructor0Args
{
    class Base
    {
        public Base(int x)
        {
        }
    }

    class Derived : Base
    {
    }         


        

Answer 1

If you don't explicitly define a constructor for a class, a default constructor is automatically defined, which looks like this:

public Derived() : base() 
{
}

You need to specify the constructor on the base class as well as which arguments to pass to it:

public Derived() : base(1) 
{
}