using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<Animal> myFavouriteAnimals = new List<Animal>();

​

        myFavouriteAnimals.Add(new Animal { Name = "Worm", Eyes = 0 });

        myFavouriteAnimals.Add(new Bird { Name = "Hawk", CanFly = true });

        myFavouriteAnimals.Add(new Bird { Name = "Penguin", CanFly = false });

        myFavouriteAnimals.Add(new Fish { Name = "Eel", CanSwimBackwards = true });

        myFavouriteAnimals.Add(new Fish { Name = "Shark", CanSwimBackwards = false });

        foreach(var animal in myFavouriteAnimals)

        {

            Console.WriteLine(animal.ToString());

        }

    }

}

​

public class Animal

{

    public string Name { get; set; }

​

    /// <summary>Number of Eyes</summary>

    /// <remarks>Not all animals have eyes, use 0 to represent no eyes</remarks>

    public virtual int Eyes { get; set; }

​

    public override string ToString()

    {

        return String.Format("{0} - Eyes:{1}", Name, Eyes);

    }

}

​

/// <summary>Vertebrates have a spine, but are also `Chordates`, they have "Camera Eyes" that are specifically 2 eyes using lenses to focus an image.</summary>

/// <remarks>http://www.madsci.org/posts/archives/1999-02/920061344.Ev.r.html#:~:text=This%20is%20the%20same%20process%20at%20work%20in,they%20retained%20the%20trait%20from%20a%20common%20ancestor.</remarks>

public class Vertebrates : Animal

{

    public override sealed int Eyes { get { return 2; } set{/*Force only 2 eyes, ignore setter*/} }

}

​

public class Bird : Vertebrates

{

    /// <summary>Not all birds can fly: penguins, emus and ostriches are some examples </summary> 

    public bool CanFly { get;set; }

​

    public override string ToString()

    {

        return String.Format("{0}, CanFly: {1}", base.ToString(), CanFly);

    }

}

​

public class Fish : Vertebrates

{

    /// <summary>Fun fact, not all fish can swim backwards! Sharks is one example</summary>

    public bool CanSwimBackwards { get;set; }

​

    public override string ToString()

    {

        return String.Format("{0}, CanSwimBackwards: {1}", base.ToString(), CanSwimBackwards);

    }

}