What are abstract classes and interfaces in C++?

What are abstract classes and interfaces in C++?

Abstract classes in C++ are classes that cannot be instantiated and are meant to be subclassed. They can contain pure virtual functions, which must be implemented by derived classes. Interfaces, on the other hand, are typically represented by abstract classes that only contain pure virtual functions.

Can you give me an example of an abstract class?

Sure! Here's a simple example:

class Shape {
public:
    virtual void draw() = 0; // Pure virtual function
};

In this example, Shape is an abstract class with a pure virtual function draw().

How do interfaces differ from abstract classes?

In C++, interfaces are usually implemented as abstract classes that only contain pure virtual functions. The main difference is that an abstract class can have member variables and concrete methods, while an interface cannot.

Can a class inherit from multiple abstract classes?

Yes, C++ supports multiple inheritance, so a class can inherit from multiple abstract classes. However, this can lead to complexity, such as the diamond problem, which you should be aware of.