Can we access private data members of a class without using a member or a friend function?

The idea of Encapsulation is to bundle data and methods (that work on the data) together and restrict access of private data members outside the class. In C++, a friend function or friend class can also access private data members.

Is it possible to access private members outside a class without friend?
Yes, it is possible using pointers. See the following program as an example.

#include<iostream> using namespace std;   class Test { private:     int data; public:     Test() { data = 0; }     int getData() { return data; } };   int main() {     Test t;     int* ptr = (int*)&t;     *ptr = 10;     cout << t.getData();     return 0; }

Output:

10

Note that the above way of accessing private data members is not at all a recommended way of accessing members and should never be used. Also, it doesn’t mean that the encapsulation doesn’t work in C++. The idea of making private members is to avoid accidental changes. The above change to data is not accidental. It’s an intentionally written code to fool the compiler.