OOP - Abstract Classes

Carl Beattie — Wed, 13 Aug 2025 00:28:05 +0000

What are abstract classes?

If you've been using or learning OOP for some time, you would've heard the words abstract classes being thrown about. I have found that those who are self-taught generally miss or skip the sections that focus on all aspects of abstraction. I think this is mainly down to its use case shining when working on large codebases and gigantic teams.

Unlike regular classes, abstract classes can't be instantiated, although they are allowed to contain concrete methods and properties. Classes that inherit from an abstract class must implement all abstract members.

Something to consider is that you don't always need abstract classes; sometimes, interfaces will be the better option. The general rule of thumb is that if in your abstract class you've just created has no state, it should be an interface. C# has a special abstract keyword for creating abstract classes.

Let's look at a quick example.

public abstract class Animal
{
    private bool isHungry = false;

    public abstract void Eat();
}

public class Cow : Animal
{
    public override void Eat()
    {
       // Implement how the Cow will eat its food. 
    }
}

I am creating these articles for my Advanced OOP roadmap for GameDev, which you can visit here over on roadmap.sh

OOP Abstraction

Carl Beattie — Wed, 13 Aug 2025 00:09:31 +0000

What is abstraction?

I'll keep it fairly short. Abstraction focuses on simplifying complex systems by modeling classes based on essential characteristics, hiding unnecessary details from the user.

Someone who buys a car does not necessarily need to know how to fix it; that will be abstracted to a mechanic. The mechanic is not required to know how to design the car; that's abstracted to the engineers.

Let's look at an example (Inheritance understanding is assumed)

public class Vehicle
{
    private float speed = 0f;

    public void Accelerate()
    {
        // Physics calculations to accelerate the vehicle
    }

    public void Decelerate()
    {
        // Physics calculations to decelerate the vehicle
    }
}

public class Car : Vehicle
{
    private int doors;
    private Color color;

    public Car(int doors, Color color)
    {
        this.doors = doors;
        this.color = color;
    }
}

public class SomeCarModel : Car
{
    private string name;

    public SomeCarModel(string name, int doors, Color color) : base(doors, color)
    {
        this.name = name;
    }
}

public class CarSpawner
{
    public CarSpawner()
    {
        SomeCarModel someCarModel = new SomeCarModel("someCar", 4, new Color(100, 100, 100));

        if (userInput.w)
        {
          someCarModel.Accelerate();
        }
    }
}

Now, someone can add a new car without worrying about creating the logic to make the car move; we have abstracted that away.

Other abstraction topics we will focus on in the future are:

Data Abstraction
Control Abstraction
Abstraction Levels
Abstract Classes

I am creating these articles for my Advanced OOP roadmap for GameDev, which you can visit here over on roadmap.sh

DEV Community: Carl Beattie

OOP - Abstract Classes

What are abstract classes?

OOP Abstraction

What is abstraction?