C++ Classes and Objects: Structure, Member Functions & The 'this' Pointer

A Class is a user-defined blueprint from which individual Objects are created. An object is an actual instance occupying physical RAM with concrete data values.

Class Declaration & Method Implementation

#include <iostream>
#include <string>

class Employee {
private:
    int id;
    std::string name;
    double salary;

public:
    // Member function to set data (using 'this' to disambiguate names)
    void setData(int id, const std::string& name, double salary) {
        this->id = id;
        this->name = name;
        this->salary = salary;
    }

    void displayProfile() const {
        std::cout << "Employee ID: " << id << " | Name: " << name << " | Salary: $" << salary << "\n";
    }
};

int main() {
    // 1. Stack Allocation (Automatic lifetime)
    Employee emp1;
    emp1.setData(101, "Alice", 85000);
    emp1.displayProfile(); // Uses dot operator (.)

    // 2. Heap Allocation (Pointer access)
    Employee* empPtr = new Employee();
    empPtr->setData(102, "Bob", 92000);
    empPtr->displayProfile(); // Uses arrow operator (->)
    delete empPtr;

    return 0;
}