What are the use cases for abstract classes in C++?

What are the use cases for abstract classes in C++?

Abstract classes in C++ are used to define interfaces and provide a base for derived classes. They allow for polymorphism and code reusability.

Can you give me an example of an abstract class?

Sure! An example would be a class Shape with a pure virtual function draw(). Derived classes like Circle and Square would implement the draw() method.

Why would I use an abstract class instead of an interface?

Abstract classes can provide default behavior and state, while interfaces only define methods without any implementation. This allows for more flexibility.

Are there any performance considerations when using abstract classes?

Yes, using abstract classes can introduce a slight overhead due to virtual function calls, but the benefits of design and maintainability often outweigh this.

What are some common mistakes to avoid when using abstract classes?

Common mistakes include not providing a clear interface, overusing abstract classes when simpler solutions exist, and failing to implement all pure virtual functions in derived classes.