What is the advantage to declare destructor as a virtual in c++ ?

[todashah]

I have idea about virtual function in c++. It is supported dynamic binding but i have no idea about what is the advantage to declare any destructor as a virtual in c++ ? Explain with suitable example....

Bye...Take Care...Give Reply

[scruggsy]

I have idea about virtual function in c++. It is supported dynamic binding but i have no idea about what is the advantage to declare any destructor as a virtual in c++ ? Explain with suitable example....

Bye...Take Care...Give Reply

Here.
Destructors are also sometimes made virtual simply to satisfy the requirement that a polymorphic class must have at least one virtual function.

[Banfa]

If you delete a class through a base class pointer then if the destructor of the base class is not virtual the destructor of the actual class is not called, the same as for any other function called though a base class pointer.

Removing a class without properly calling its destructor could have serious implications for program stability.

[SpecialKay]

you can avoid memorie leaks.

[mvjohn100]

For work with "dynamic_cast" the class should have a virtual table. so to have a virtual table at least one member function should be virtual. making destructor as virtual satisfy the demand.

[haneeshkb]

I have idea about virtual function in c++. It is supported dynamic binding but i have no idea about what is the advantage to declare any destructor as a virtual in c++ ? Explain with suitable example....

Bye...Take Care...Give Reply

virtual destructer is used so that while deleting the pointer to base class but pointing to base class invokes the derived class destructor first,then the base class destruct hence preventing memory leak...

First pls get clear with virtual function concepts...
suppose we have a class hierachy
Empl-->Manager-->CEO
now we are creating
Empl* e1;
CEO c1;
e1= & c1;
Now when ever my e1 goes out of scope because e1 is of type Empl ,only the destructor of e1 is called & memory is freed for attributes of e1 only. so we have the memory leakage problem
so if we are making Destructor as a virtual so exceutin of destructor will follow
~CEO-->~Manager-->~Empl path so Memory for all the data is freed.....
so to avoid these Memory Leakage problem we have to make destructor as a virtual destructor.....

[weaknessforcats]

I just published this article in the C/C++ HowTos. Your answer is there.

http://bytes.com/forum/thread793836.html.