The derived class cannot access private members of a base class:
class MyBaseClass { private: /*w w w . ja v a2 s .co m*/ char c; int x; }; class MyDerivedClass : public MyBaseClass { // c and x NOT accessible here }; int main() { MyDerivedClass o; o.c = 'a'; // Error, not accessible to object o.x = 123; // error, not accessible to object }