dot (.) operator in C++

dot (.) operator in C++ is used to access members (data and functions) of a class, struct, or union through an object. It allows direct interaction with an object’s components.

• The dot (.) operator accesses member variables and functions using objects (not pointers) and is used for direct member access.
• It has very high precedence in C++, just below brackets, and shares the same level with the arrow (->) operator.
• The arrow (->) operator works similarly but accesses members through pointers instead of objects.
• The dot (.) operator cannot be overloaded, and attempting to do so causes compile-time errors.

#include <iostream>
using namespace std;

class Student {
public:
    int roll;

    void show() {
        cout << "Roll number is: " << roll << endl;
    }
};

int main() {
    Student s;      
    s.roll = 10;    
    s.show();       

    return 0;
}

Roll number is: 10

Syntax

variable_name.member;

• variable_name: It's an instance of a class, structure, or union.
• member: member variables or member functions associated with the created object, structure, or union.

#include <iostream>
using namespace std;

class Car {
public:
    string model;
    int year;

    Car(string m, int y) {
        model = m;
        year = y;
    }

    void showDetails() {
        cout << "Model: " << model << endl;
        cout << "Year: " << year << endl;
    }
};

int main() {
    
    Car c("BMW", 2024);

    cout << "Accessing data members:" << endl;
    cout << c.model << endl;
    cout << c.year << endl;

    cout << "Accessing member function:" << endl;
    c.showDetails();

    return 0;
}