Assertion: interface's state | /r/HasProperty | data members
Facets:
Source sentences:
text: Virtual destructor makes sure that when a shape is deleted polymorphically, correct destructor of the derived class is invoked.1 - interfaces can have no state or implementation2 - a class that implements an interface must provide an implementation of all the method of that interface3 - abstract classes may contain state (data members) and/or implementation (methods)4 - abstract classes can be inherited without implementing the abstract methods (though such a derived class is abstract itself)5 -interfaces may be multiple-inherited, abstract classes may not (- they permit an implementation of multiple inheritance that removes many of the problems of general MI).6-