C# acces property from abstract classes

Question

I have a class structure like this:

BaseAnimal.cs:

public abstract class BaseAnimal
{
   public string? Species { get; set; }
   public double Price { get; set; }
}

Then I have this two classes:

public abstract class Carnivore : BaseAnimal
{
    public double MeatFood { get; set; }
}

public abstract class Herbivore : BaseAnimal
{
   public double GreenFood { get; set; }
}

And then I have the sub classes:

public class Ape : Herbivore
{
    public Ape()
    {
        Species = "Ape";
        GreenFood = 10.0;
        Price = 10000.0;
    }
}

Then I have a facotry which is already working with this line to get all the attributes from an animal:

public BaseAnimal[] Animals = prototypes.Values.ToArray();

And in my Main class I would like to read the properties of the Animals:

 private void cboAnimals_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
    Debug.WriteLine(animalFactory.Animals[0].);
 }

The problem with this code is, that I cannot access the properties specified in the Herbivore.cs and Carnivore.cs

Answer 1

Simplest is probably to check the type:

var foodAmount = animalFactory.Animals[0] switch {
     Carnivore c => c.MeatFood ,
    Herbivore h => h.GreenFood ,
    _ => throw new InvalidOperationException()
};

But this is a typical example of inheritance taught in introductory programming. As a general rule, if you need to check the type, you might not have thought thru your type system well enough. The idea with inheritance is that everything implementation specific should be delegated to the implementation, so the user of the object do not need to know the concrete type.

I have some difficulty providing concrete recommendations since the example is so artificial, But I would recommend reading Eric Lippert series on Wizards and Warriors for a nice introduction to inheritance, and how people often do it wrong.