Interfaces and data abstraction in C++ programming

Shailendra Chauhan 7 min read

21 Jul 2023

Intermediate

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Interfaces and data abstraction in C++ programming

Introduction

If you are a C++ programmer - either new or experienced, undergoing C++ training, you know that interfaces and data abstraction can make your code much simpler and easier to maintain. You may understand the concept of classes, but do you fully understand how they interact with each other? In this blog post, focused on C++, I’m covering all the fundamentals of interfaces and data abstraction in programming. By reading this article until the end, you will gain knowledge regarding these topics and be able to apply it to your projects for real-world applications. So don't miss out on all the important information!

What is Interface in C++

Interfaces in C++ programming language are interface classes that define abstract classes that contain no data members. Interfaces are used to enforce a contract between components to provide type safety within an application. Interfaces have been around since the dawn of C++ programming language and have proven to be an efficient way to create loosely coupled resilient systems. Interfaces allow developers to create highly portable code, while also providing robustness by enforcing contracts across applications. Interfaces in C++ programming language can help to increase code reusability and extensibility, as well as make testing simpler due to its modular approach. Interfaces are an indispensable part of any large-scale software system and should be leveraged when developing with C++ for maximum benefits.

Importance of interfaces in C++

Any class that is derived from the pure abstract classes which are called Interface must be implemented by all of the methods of the base class.
The pointers in Interface can be passed to classes and functions thereby the programmers as well as the user can call the functions of the derived class from that particular class.

Rules of using Interfaces in c++

The users have to declare only pure virtual functions without giving their definition
For pure virtual functions, the users can only assign 0.
The user cannot create an instance of the class.
Users can only create a pointer to the instance of a particular derived class with a reference to a base class, or Abstract Classes

Example

// C++ program to implement
// Interface
#include <iostream>
#include <string>
using namespace std;
// Interface(Abstract class
// with pure virtual function)
class Scholar
{
public:
    virtual string returnString() = 0;
};
class child : public Scholar
{
public:
    string returnString()
    {
    return "ScholarHat";
    }
};
int main()
{
    child childObj;
    Scholar* ptr;
    ptr = &childObj;
    cout << ptr->returnString();
    return 0;
}

Output

ScholarHat

What is Data Abstraction in C++

Data abstraction in C++ programming language is a feature that allows programmers to create new data types and manipulate them without having to consider their actual implementation. Data abstraction enables users to write data-driven code without having to be concerned about the underlying structure of the data. Data abstraction is generally achieved by using classes, which are collections of related variables and functions that can be used to store and manipulate various types of data. Data abstraction helps provide flexibility in how users interact with their existing programs, as it allows for easier integration with other software systems. Data abstraction also helps improve program readability, as relevant information remains separated from lower-level implementation details. Data abstraction in C++ programming language is an invaluable tool for any programmer looking to simplify their coding experience and maximize the efficiency of their programs.

Example

// C++ Program to Demonstrate the
// working of Abstraction
#include <iostream>
using namespace std;
class implementAbstraction
{
private:
    int A, B;
public:
    // method to set values of
    // private members
    void set(int x, int y)
    {
        A = x;
        B = y;
    }
    void display()
    {
        cout << "A = " << A << endl;
        cout << "B = " << B << endl;
    }
};
int main()
{
    implementAbstraction obj;
    obj.set(20, 30);
    obj.display();
    return 0;
}

Output

A= 20
B= 30

Advantages of Data abstraction in C++

Data abstraction in c++ programming language helps the developers as well as users to avoid writing any low-level code
This particular feature helps to avoid code duplication thus it increases reusability.
Data abstraction can independently change the internal implementation of the class without affecting the user.
Data abstraction helps to boost the security of a program or application because only the important details are provided to the user.
This particular feature reduces the redundancy as well as the complexity of the program, so it increases the readability of the code.

Different ways of data abstraction in C++

Abstraction using classes

Abstraction in c++ programming language can be implemented in classes. The class helps the programmers to group the members of that data and function by using available access specifiers. A class is the main deciding factor of which data member will be visible to the world or which is not.

Abstraction using header files

Another type of abstraction in the c++ programming language is related to header files. For instance, let's consider the pow() method present in the math.h header file. If the developer needs to calculate the power of a number, then it is called the function pow() which is present in the math.

Summary

To conclude, interfaces and data abstraction are two important aspects of object-oriented programming in C++. By understanding and making use of these concepts, you can make your code more efficient and easier to manage. So, practice in C++ certification training – and don’t be afraid to experiment with these techniques in your own projects. Want to learn more about interfaces and data abstraction? Check out our other blog post on the subject.