CareerCup

Correct answer

I really wonder if Polymorphism is the correct answer. In the below code the parent pointer points to a derived object, but compilation error will be thrown when this parent pointer tries to access a function which is there only in Derived class object

#include <iostream>
using namespace std;

class B
{
        public: virtual void fun() {cout<<"Base"<<endl;};
};

class D2:public B
{
        public: virtual void fun() {cout<<"der2"<<endl;};
        public: virtual void OnlyInDerived() {cout<<"fun1"<<endl;};
};


main()
{
        D2 d;
        B *b=&d;
        b->OnlyInDerived();
}

I think its polymorphism. You will not worry about exact class if a base class ref/pointer holds base/derived class object

is there any reason why you have chosen abstraction?

I'm sure the expected answer is polymorphism. Certainly, though, polymorphism does contribute to abstraction.