C++ Class Methods

1. Basic Class Method Example

Example of defining and using class methods:

#include <iostream>
#include <string>

// Class declaration
class Circle {
private:
    double radius;

public:
    // Constructor
    Circle(double r) {
        radius = r;
    }

    // Member function to calculate area
    double calculateArea() {
        return 3.14159 * radius * radius;
    }

    // Member function to calculate circumference
    double calculateCircumference() {
        return 2 * 3.14159 * radius;
    }
};

int main() {
    // Create object of class Circle
    Circle circle1(5.0);

    // Call member functions to calculate area and circumference
    double area = circle1.calculateArea();
    double circumference = circle1.calculateCircumference();

    // Display results
    std::cout << "Area of circle: " << area << std::endl;
    std::cout << "Circumference of circle: " << circumference << std::endl;

    return 0;
}

2. Static Methods

Example of static methods in a class:

#include <iostream>
#include <string>

// Class declaration
class MathUtility {
public:
    // Static method to calculate factorial
    static int factorial(int n) {
        if (n == 0 || n == 1) {
            return 1;
        } else {
            return n * factorial(n - 1);
        }
    }

    // Static method to calculate square
    static int square(int num) {
        return num * num;
    }
};

int main() {
    // Call static methods directly using class name
    int fact = MathUtility::factorial(5);
    int squareNum = MathUtility::square(7);

    // Display results
    std::cout << "Factorial of 5: " << fact << std::endl;
    std::cout << "Square of 7: " << squareNum << std::endl;

    return 0;
}

3. Constant Methods

Example of constant methods in a class:

#include <iostream>
#include <string>

// Class declaration
class Person {
private:
    std::string name;
    int age;

public:
    // Constructor
    Person(std::string n, int a) : name(n), age(a) {}

    // Constant member function to display person's info
    void displayInfo() const {
        std::cout << "Name: " << name << ", Age: " << age << std::endl;
    }
};

int main() {
    // Create object of class Person
    const Person person("Alice", 30);

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

    return 0;
}

Conclusion

Class methods in C++ are member functions that operate on class objects, allowing manipulation of object data and behavior. This chapter covered basic class methods for calculating area and circumference, static methods for factorial and square calculations, and constant methods for accessing object data without modification. Understanding class methods enables you to design and implement efficient and maintainable C++ classes.