Base* optr=new Derived();
delete optr;
I know that if Base class has a non-virtual destructor, only ~Base() destructor is going to be called when deleting optr pointer. But I found out that even without ~Derived() destructor being called the memory that was taken by the Derived Object was freed. So my question is can an object get freed without calling it's destructor?
If the answer is yes, can I use a non-virtual destructor if my Derived class does not contain any dynamically allocated variables so I don't care if it did not get called?
From the viewpoint of standard C++, the answer is simple: the result is undefined behavior, so what you get is completely unpredictable
I'm a little puzzled why you'd care anyway. If you can eliminate all the virtual functions from a class, each instance becomes smaller (by the size of a vtable pointer). Using such a thing as a base class rarely makes sense though -- for use as a base class to be sensible, you pretty much need to have at least one virtual function in the base for the derived class to override. Once you have a virtual function (any virtual function) adding more is essentially free -- objects don't grow any larger by adding more virtual functions.
To answer your question directly: yes, the memory can be freed without the destructor being invoked. The real question is what will happen when you make that happen (and there's really no answer to that question).