Object-Oriented Programming in C++ and interview questions

Introduction:

Object-Oriented Programming (OOP) has revolutionized the way software is designed and implemented. C++, a versatile programming language, is renowned for its support and robust implementation of OOP concepts. In this article, we will delve into the fundamental principles of Object-Oriented Programming in C++ and explore how it enhances code modularity, reusability, and maintainability.

1. Classes and Objects:

1. At the core of OOP in C++ are classes and objects. A class is a blueprint that defines the attributes (data members) and behaviors (member functions) of objects. Objects, on the other hand, are instances of classes. This paradigm allows developers to structure their code in a way that mirrors real-world entities, promoting a more intuitive and modular design.
2. EXAMPLE:-

// Example of a simple class in C++
class Car {
public:
    // Attributes
    string brand;
    int year;
    
    // Behavior
    void displayInfo() {
        cout << "Brand: " << brand << ", Year: " << year << endl;
    }
};

// Creating objects of the Car class
Car car1;
car1.brand = "Toyota";
car1.year = 2022;
car1.displayInfo();
);

2. Encapsulation:

2. Encapsulation is the bundling of data and methods that operate on the data within a single unit, i.e., a class. Access specifiers like private, public, and protected control the visibility of members outside the class. This ensures that the implementation details are hidden, promoting data security and abstraction.
3. EXAMPLE:-
4. C++ Object-Oriented Programming Examples:-
5. 
   
6. class BankAccount { private: double balance; public: // Public method to access private member void deposit(double amount) { balance += amount; } // Public method to access private member void withdraw(double amount) { if (amount <= balance) { balance -= amount; } else { cout << "Insufficient funds." << endl; } } // Public method to access private member double getBalance() { return balance; } };


7. 
   

2. Inheritance:

3. Inheritance allows a class to inherit the properties and behaviors of another class, promoting code reuse. The base class (parent) provides a common structure, and the derived class (child) can extend or modify it as needed.
4. EXAMPLE:-
C++ Object-Oriented Programming Examples:-

5. // Base class class Shape { public: virtual void draw() { cout << "Drawing a shape." << endl; } }; // Derived class class Circle : public Shape { public: void draw() override { cout << "Drawing a circle." << endl; } };

3. Polymorphism:
4. Polymorphism allows objects of different types to be treated as objects of a common type. In C++, polymorphism is achieved through function overloading and virtual functions. This enables flexibility in code design and facilitates the creation of more extensible and adaptable systems.
5. EXAMPLE:-
C++ Object-Oriented Programming Examples

6. class Animal { public: virtual void makeSound() { cout << "Generic animal sound." << endl; } }; class Dog : public Animal { public: void makeSound() override { cout << "Woof! Woof!" << endl; } }; class Cat : public Animal { public: void makeSound() override { cout << "Meow!" << endl; } };


7. Conclusion:

Object-Oriented Programming in C++ brings a powerful and elegant approach to software development. By embracing the principles of classes, objects, encapsulation, inheritance, and polymorphism, developers can create well-structured, modular, and maintainable code. As you delve deeper into the world of C++ OOP, you'll discover how these concepts work together seamlessly to unlock the full potential of your software projects.