Classes

.NET Abstract Classes

Abstract Classes

.NET abstract classes define blueprints with abstract members.

Introduction to Abstract Classes

In .NET, abstract classes serve as blueprints for other classes. They cannot be instantiated directly and are designed to be inherited by other classes. Abstract classes can include abstract methods, which must be implemented in derived classes, as well as non-abstract methods, which can provide a common implementation to be shared among all derived classes.

Defining an Abstract Class

To define an abstract class in C#, use the abstract keyword. This keyword indicates that the class is incomplete and intended to be a base class for other classes.

Here's a simple example of an abstract class:

Implementing Abstract Members

Abstract methods are declared with the abstract keyword and do not have a body. When a class inherits an abstract class, it must provide implementations for all its abstract methods. Let's see how this works:

Using Abstract Classes

Although you cannot instantiate an abstract class directly, you can use it as a reference type. This allows you to create a collection of abstract type objects, which can be populated with instances of derived classes:

Benefits of Using Abstract Classes

Abstract classes provide several benefits:

Code Reusability: Common behavior can be implemented once in the abstract class and reused in derived classes.
Enforced Structure: Derived classes are required to implement abstract methods, ensuring a consistent interface.
Flexibility: Non-abstract methods in abstract classes can provide default functionality, which can be overridden if needed.

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