using System;

public class Program

{

    public static void Main()

    {

        var classes =  new BaseClass[]{new BaseClass(),new OtherClass(),new WorldClass()};

        for(var i = 0; i < 3; i++ ) classes[i].WriteToConsole();

    }

}

​

public class BaseClass

{

    public virtual void WriteToConsole(){

        Console.WriteLine("I'm a base class.");

    }

}

​

public class OtherClass : BaseClass

{

    public void WriteToConsole(){

        Console.WriteLine("I'm Other class.");

    }

}

​

public class WorldClass : BaseClass

{

    public override void WriteToConsole(){

        Console.WriteLine("I'm World class.");

    }

}