When should I use abstract classes in C++?

When should I use abstract classes in C++?

Abstract classes in C++ are used when you want to define a common interface for a group of related classes, but you don't want to provide a complete implementation. They allow you to enforce certain methods to be implemented in derived classes.

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
};

class Circle : public Shape {
public:
    void draw() override {
        // Implementation for drawing a circle
    }
};

class Square : public Shape {
public:
    void draw() override {
        // Implementation for drawing a square
    }
};

What are the benefits of using abstract classes?

The benefits include:

1. Code reusability: You can define common behavior in the abstract class.
2. Flexibility: You can change implementations in derived classes without affecting the base class.
3. Enforced structure: Derived classes must implement the abstract methods, ensuring a consistent interface.

Are there any downsides to using abstract classes?

Yes, some downsides include:

1. Increased complexity: It can make the code harder to understand.
2. Overhead: There may be a slight performance overhead due to virtual function calls.
3. Design rigidity: It can lead to a rigid design if not used carefully.