Possible Duplicate:
Calling virtual functions inside constructors
in C++, An object of class B derived from class A, in C++ the c’tor of A is invoked before the c’tor of B , why ? And what happens if A’s C’tor invokes a virtual function? does it invoke A's virtual function of B's ?
Most of your questions, if not all, are covered by the C++ FAQ.
E.g. see the FAQ "When my base class's constructor calls a virtual function on its this object, why doesn't my derived class's override of that virtual function get invoked?".
It is always a good idea to read the FAQ before asking.
