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It is a good programming practice to keep the destructor virtual if your base class has any virtual function that is overridden in derived class.

Yes I do believe that there is need to keep the destructor virtual in the above when you have not allocated anything on the heap. Bcos objects on heap would clean up on its when when the derived class goes out of scope

If base class or derived class object is not created dynamically then there is no need for virtual destructor......

run following code:

class Base{
public:
~Base(){cout<<"Base::~Base()"<<endl;}
};

class Derived:public Base{
public:
~Derived(){cout<<"Derived::~Derived()"<<endl;}
};

int main(){
Derived d;
Base* p = new Derived;
delete p;
cout<<"======="<<endl;
}

Derived object created on stack, Derived, Base destructor will be called in order
However, Derived object created on heap, the behavior is UNDEFINED! Therefore, even no members that are allocated on heap, and none virtual destructor for Base works fine on your machine and compiler, you cannot guarantee it works correctly on other machine and compiler.

No. it is not required if the members are not allocated dynamically.But as a standard any class eligible to be a base class needs to have virtual destructor.

But how about static member data? If the derived class has a static member used to record number of instantiated objects, the number increments in its constructor, and decrements in destructor. If only the base class destructor be called, that static member will not work correctly.

..."members that are allocated on heap" are not the only resources one must free up properly in a destructors. Graphoical resources, n/w (e.g. open sockets), mutexes etc: why do you for get ab. all these?

Agree with Anonymous on April 25, 2010.

In addition, Derived's data members won't be destroyed properly. Their destructors will not get called which is bad.

if we are assured of that there will be no use of heap then we should go for no-virtual destructor because using virtual destructor will cause an extra vtbl pointer in the object which do not have any need in this situation except that it will increase the processor instruction and pollute cahce.