CareerCup

Base::Display is non-virtual, which means that when you call it there isn't a v-table lookup, so it just calls based on the static type of the pointer (in this case Base).

This cannot a google interview question. This is basic rule of inheritance+ virtual function
if base class does not have virtual function ==-> function calling is based on type of pointer
and if the base class contain a virtual function then that function will be called on the base of content of the pointer.


So in this case the display is not virtual.. to the display of base class is called because you are accessing it via base class pointer.

try to run this code

#include <iostream>
using namespace std;

class Base {
public:
char* name;
virtual void display() {
cout << name << endl;
}
};

class Derived: public Base {
public:
char* name;
void display() {
cout << name << ", " << Base::name << endl;
}
};

int main() {
Derived d;
d.name = "Derived Class";
d.Base::name = "Base Class";

Derived* dptr = &d;

// standard conversion from Derived* to Base*
Base* bptr = dptr;

// call Base::display()
bptr->display();
}

in the code the display() drived class will be called as content of base pointer is a address of drived calls instance..that is the content of the pointer is a drived class.

Is this really Google's question?

base class pointer doesnt have scope to point to derive class in any condition...

make the display function as virtual in base class, then it works as expected..

virtual display();

Who are all answering should understand that it is not quality of question that matters, it is quality of answer you give, I know about Amazon/Google interviews where they have asked program to find prime number. Every Google interviewer has his own bar while interviewing. Some usually like to start with simple program like reverse a string first check how the candidate can think and see if we can code.Then only tougher questions and stronger discussions could be made.
So, rather than commenting on how simple questions it kindly, recommended to provide quality answers.

this cant be a google interview question.. patilsanketv - you are lucky enough to answer this kind of question especially in Google interviews..

Although Base::display is not a virtual method, the Derived::display will explicitly output Base::name which contains "Base Class".

come on man!!! If you dont come, someone else will come on.

po raa

thanks for your ans :)

i lov you shakela....

thanks for your ans jeelabi.....

i want to write answer??

It is hsowing the answer as Derived Class, Base Class