C++ Class Program

C++ classes are an essential part of object-oriented programming (OOP). They provide a blueprint or template for creating objects with specific attributes and behaviors. In this article, we will explore how to create a C++ class program with examples.

1. Creating a Class

To create a class in C++, you use the class keyword followed by the class name. Here's an example:

#include <iostream>
#include <string>

// Define a class
class Person {
private:
    std::string name;
    int age;

public:
    // Constructor
    Person(const std::string& _name, int _age) : name(_name), age(_age) {}

    // Member function
    void displayInfo() {
        std::cout << "Name: " << name << std::endl;
        std::cout << "Age: " << age << std::endl;
    }
};

int main() {
    // Create an object of the class
    Person person("John Doe", 25);

    // Call the member function
    person.displayInfo();

    return 0;
}

In the above code, we define a class named Person with two private member variables: name and age. We also have a constructor that initializes these variables. Additionally, we have a member function displayInfo() that outputs the person's name and age. In the main() function, we create an object of the class Person and call its displayInfo() member function.

2. Access Specifiers

C++ provides access specifiers (public, private, and protected) to control the access to class members. Here's an example:

#include <iostream>
#include <string>

class Rectangle {
private:
    double length;
    double width;

public:
    Rectangle(double _length, double _width) : length(_length), width(_width) {}

    double calculateArea() {
        return length * width;
    }
};

int main() {
    Rectangle rectangle(5.0, 3.0);

    double area = rectangle.calculateArea();
    std::cout << "Area: " << area << std::endl;

    return 0;
}

In the above code, we define a class Rectangle with two private member variables: length and width. We also have a constructor and a member function calculateArea() that calculates and returns the area of the rectangle. In the main() function, we create an object of the class Rectangle and call its calculateArea() member function.

3. Class Inheritance

Inheritance allows you to create a new class based on an existing class. The derived class inherits the properties and behaviors of the base class. Here's an example:

#include <iostream>
#include <string>

class Animal {
public:
    void makeSound() {
        std::cout << "The animal makes a sound." << std::endl;
    }
};

class Dog : public Animal {
public:
    void makeSound() {
        std::cout << "The dog barks." << std::endl;
    }
};

int main() {
    Animal animal;
    animal.makeSound();

    Dog dog;
    dog.makeSound();

    return 0;
}

In the above code, we define a base class Animal with a member function makeSound(). We then define a derived class Dog that inherits from the Animal class. The Dog class overrides the makeSound() member function. In the main() function, we create objects of both classes and call the makeSound() member function for each object.

C++ classes provide a structured and modular way to organize your code. By encapsulating data and behavior within a class, you can create objects that possess specific attributes and actions. Utilize classes to design and implement complex systems effectively in your C++ programs.