Object Oriented Programming Logic

Question

I am learning basic concepts of OOP in C++ and I came across a logical problem.

#include <iostream>
#include <conio.h>

using namespace std;

class A {
    int i;
public:
    void set(int x) {
        i=x;
    }
    int get() {
        return i;
    }
    void cpy(A x) {
        i=x.i; 
    }
};

int main()
{
    A x, y;
    x.set(10);
    y.set(20);

    cout << x.get() << "\t" << y.get() << endl;
    x.cpy(y);
    cout << x.get() << "\t" << y.get() << endl;
    getch();
}

I wanted to know in the above code why am I able to access x.i [Line 19] ,it being a private member in the different object.Isn't the private scope restricted to the same class even if the object is passed as a parameter?

Answer 1

private in C++ means private to the class, not private to the object. Both interpretations are possible, indeed some languages chose the other. But most languages are like C++ in this and allow objects of the same class to acces another instance’s private members.

Answer 2

Variables x and y are two instances of the same class. They are different objects but they do belong to the same class. That's why is it possible to access the private member from the member function.