output of the program???

[ujjwal bhoota]

Hi,
Can any one explain me the behaviour of following program.




#include <iostream>

using namespace std;

class A {
public:
A() {
this->Foo();
}
virtual void Foo() {
cout << "A::Foo()" << endl;
}
};



class B : public A {
public:
B() {
this->Foo();
}
virtual void Foo() {
cout << "B::Foo()" << endl;
}
};






int main(int, char**)
{
B objectB;

return 0;
}



The output is

A::Foo()
B::Foo()



should not it be

B::Foo()
B::Foo()
as B::Foo() has been declared to be virtual


thanks and regards
UJJWAL

 

[lilburne]

The output is

A::Foo()
B::Foo()



should not it be

B::Foo()
B::Foo()
as B::Foo() has been declared to be virtual

B has not been constructed until after the A constructor has
finished, therefore there is no B for B::foo() to be called
whilst in A's constructor.