How to implement Member functions in cpp.

#include <iostream>
#include <string>

class Person {
private:
    std::string name;
    int age;

public:
    Person(const std::string& n, int a) : name(n), age(a) {}

    void introduce() {
        std::cout << "Hello, I'm " << name << " and I'm " << age << " years old." << std::endl;
    }

    void celebrateBirthday() {
        ++age;
        std::cout << "Happy Birthday! Now I'm " << age << " years old." << std::endl;
    }
};

int main() {
    Person person1("Alice", 25);
    Person person2("Bob", 30);

    person1.introduce();
    person2.introduce();

    person1.celebrateBirthday();
    person2.celebrateBirthday();

    person1.introduce();
    person2.introduce();

    return 0;
}