Data Abstraction & Interfaces in C++

What is Data Abstraction in C++?

In C++, data abstraction means providing only the data needed to the outside world while hiding internal details, such as background details or implementation. Abstraction is a programming method that involves separating the program's interface from its implementation details.

Methods for implementing Data Abstraction in C++

There are 2 methods for implementing Data Abstraction in C++:

1. Abstraction using Classes
2. Abstraction using Header Files

Abstraction with classes

Abstraction in the C++ programming language can be implemented via classes. The class assists programmers in grouping the members of that data and function utilizing accessible access specifiers. A class determines whether or not a data member is visible to the rest of the world.

Abstraction with header files

Another sort of abstraction in the C++ programming language is associated with header files. For example, consider the pow() method in the math.h header file. If the developer needs to calculate the power of an integer, he or she can use the function pow() found in math.

Abstraction with Access Specifiers

Access specifiers are the basis for implementing abstraction in C++. We can use access specifiers to set limits on class members. For example:

• Members defined as public in a class are accessible from anywhere in the program.
• Members defined as private in a class can only be accessed from within that class. They cannot be accessed from anywhere in the code other than the class.

Advantages of Data Abstraction in C++

• Data abstraction in C++ removes the requirement for low-level programming.
• Reduces code duplication, increasing reusability.
• Allows for independent modifications to a class's internal implementation without affecting users.
• Increases program security by disclosing only essential facts to the user.
• Reduces redundancy and complexity, which improves code readability.

What is an Interface in C++?

In C++, an interface is often represented as an abstract class that only has pure virtual functions. It allows you to construct a contract for which methods a class should implement without describing how they should be implemented.

Importance of Interfaces in C++

• Any class derived from an Interface must implement all of its methods.
• Classes and functions accept interface references.
• This enables programmers and users to access functions of the derived class via the interface.
• Ensures that the derived class methods are implemented and used consistently.

How to Use Interfaces in C++?

• The users must declare only pure virtual functions without disclosing their definitions.
• For pure virtual functions, users can only assign 0.
• The user is unable to make an instance of the class.
• Users can only generate a pointer to the instance of a certain derived class using a reference to a base class, or abstract classes.