C++ Abstraction Interfaces

Abstraction is a programming technique that helps in representing complex data types or operations in a simple and easy to understand way. Abstraction interfaces in C++ provide a way to define abstract classes and pure virtual functions. These abstract classes cannot be instantiated but are meant to be implemented by derived classes.

Syntax

class AbstractClass {
public:
    virtual void pureVirtualFunction() = 0;
};

Example

#include <iostream>

class AbstractClass {
public:
    virtual void pureVirtualFunction() = 0;
};

class DerivedClass : public AbstractClass {
public:
    void pureVirtualFunction() {
        std::cout << "Derived class implementation of pure virtual function.\n";
    }
};

int main() { 
    AbstractClass* abstractObject = new DerivedClass(); 
    abstractObject->pureVirtualFunction();
    delete abstractObject;
    return 0; 
};

Output

Derived class implementation of pure virtual function.

Explanation

In this example, we define an abstract class AbstractClass with a pure virtual function pureVirtualFunction(). This abstract class cannot be instantiated and is meant to be implemented by the derived classes.

We also define a derived class DerivedClass which inherits AbstractClass and implements pureVirtualFunction() with its own implementation.

In the main function, we create a pointer object abstractObject of the AbstractClass and assign it to a new object of DerivedClass. We then call the pure virtual function through the abstractObject pointer which calls the pureVirtualFunction() implementation of DerivedClass.

Use

Abstraction interfaces in C++ are used to create classes with pure virtual functions that are meant to be implemented by the derived classes. This is useful in situations where we need to implement a common set of methods or functions that are used by different classes but have different underlying implementations.

Important Points

• Abstraction interfaces are defined using abstract classes and pure virtual functions
• Abstract classes cannot be instantiated and are meant to be implemented by derived classes
• Pure virtual functions have no implementation and must be defined in the derived classes
• Abstraction interfaces enable polymorphism and dynamic binding in C++

Summary

Abstraction interfaces in C++ are a powerful programming technique that provides a simple and easy to understand way to represent complex data types or operations. They are used to define abstract classes and pure virtual functions that are meant to be implemented by derived classes. This enables polymorphism and dynamic binding, which is useful in situations where we need to implement a common set of methods or functions that are used by different classes but have different underlying implementations.