C++ Programming: A Practical Approach

288 C++ Programming

When object a2 goes out of scope, the derived class object b2 on stack should be automatically

reclaimed (deleted) which will not happen as the derived class destructor will not be called.

Hence, one should declare the destructor of base class – class A – as virtual. When a base class

contains at least one virtual or pure virtual function, it must declare the destructor virtual. This

avoids undefined behaviour which may be caused when an attempt is made to delete the de-

rived class object through a base class pointer. Let me give one practical example. One should

carry an umbrella in the rainy season even though it may not ...