What is an Abstract Class in C# with Example?

When it comes to object-oriented programming, abstract classes are a crucial concept. An abstract class is a restricted class that cannot be used to create objects. To access it, it must be inherited from another class. Abstract classes are used to provide a common definition of a base class that multiple derived classes can share.

In this article, we will explore what an abstract class is in C# and provide an example of how to use it.

What is an Abstract Class?

An abstract class is a special type of class that cannot be instantiated. This means that you cannot create an object of an abstract class. An abstract class is used to provide a common definition of a base class that multiple derived classes can share.

An abstract class contains one or more abstract methods. An abstract method is a method that is declared, but not implemented in the code. It can only be used in an abstract class, and it does not have a body. Instead, the body of an abstract method is provided by the derived class.

When to Use an Abstract Class

An abstract class is used when you want to provide a common definition of a base class that multiple derived classes can share. This is useful when you want to create a base class that contains common methods and properties that can be used by all the derived classes.

For example, if you have a base class called “Animal” and you want to create derived classes for “Dog”, “Cat”, and “Horse”, you can use an abstract class to define the common properties and methods that all animals have.

How to Create an Abstract Class in C#

Creating an abstract class in C# is relatively straightforward. To create an abstract class, you simply need to use the “abstract” keyword before the class name.

For example, if you wanted to create an abstract class called “Animal”, you would use the following code:

public abstract class Animal
{

}

Once you have created the abstract class, you can then add abstract methods to it. To create an abstract method, you simply need to use the “abstract” keyword before the method name.

For example, if you wanted to create an abstract method called “Move”, you would use the following code:

public abstract void Move();

Creating an Abstract Method in C#

Once you have created an abstract class, you can then create abstract methods within it. To create an abstract method, you simply need to use the “abstract” keyword before the method name.

For example, if you wanted to create an abstract method called “Move”, you would use the following code:

public abstract void Move();

The abstract method does not have a body, so you do not need to provide any code within the method. Instead, the body of the method will be provided by the derived class.

Using an Abstract Class in C#

Once you have created an abstract class, you can then use it in your code. To use an abstract class, you simply need to create a derived class that inherits from the abstract class.

For example, if you wanted to create a derived class called “Dog” that inherits from the “Animal” abstract class, you would use the following code:

public class Dog : Animal
{

}

Once you have created the derived class, you can then provide the body for the abstract methods in the abstract class.

For example, if you wanted to provide the body for the “Move” method in the “Dog” class, you would use the following code:

public override void Move()
{
// Code to move the dog
}

Conclusion

In this article, we have explored what an abstract class is in C# and provided an example of how to use it. An abstract class is a special type of class that cannot be instantiated and is used to provide a common definition of a base class that multiple derived classes can share. To create an abstract class, you simply need to use the “abstract” keyword before the class name. To create an abstract method, you simply need to use the “abstract” keyword before the method name. To use an abstract class, you simply need to create a derived class that inherits from the abstract class and provide the body for the abstract methods in the derived class.