Basic example of inheritance in C++

basic_inheritance.cpp

#include <iostream>
using namespace std;

class Device {
    public:
        int serial_number = 12345678;

        void turn_on() {
            cout << "Device is on" << endl;
        }
    private:
        int pincode = 87654321;
};

class Computer: public Device {};

int main() {
    Computer Computer_instance;
    
    Computer_instance.turn_on();
    cout << "Serial number is: " << Computer_instance.serial_number << endl;
    // cout << "Pin code is: " << Computer_instance.pincode << endl;
    // will cause compile time error

    return 0;
}