Can a derived class have a virtual destructor?

Can a derived class have a virtual destructor?

Deleting a derived class object using a pointer of base class type that has a non-virtual destructor results in undefined behavior. To correct this situation, the base class should be defined with a virtual destructor.

Do derived classes inherit destructors?

Derived classes do not inherit or overload constructors or destructors from their base classes, but they do call the constructor and destructor of base classes.

Does a derived class need a destructor?

No. You never need to explicitly call a destructor (except with placement new). A derived class’s destructor (whether or not you explicitly define one) automagically invokes the destructors for base class subobjects. Base classes are destructed after member objects.

Can derived class be virtual?

Virtual Functions in Derived Classes in C++ When you use a pointer or a reference to the base class to refer to a derived class object, you can call a virtual function for that object and have it run the derived class’s version of the function.

Does abstract class need virtual destructor?

It is important to note that a class becomes an abstract class(at least a function that has no definition) when it contains a pure virtual destructor.

Why does a class destructor sometimes have to be specified as virtual?

The implicitly-declared destructor is virtual (because the base class has a virtual destructor) and the lookup for the deallocation function (operator delete()) results in a call to ambiguous, deleted, or inaccessible function.

Are virtual destructors inherited?

Yes, they are the same. The derived class not declaring something virtual does not stop it from being virtual. There is, in fact, no way to stop any method (destructor included) from being virtual in a derived class if it was virtual in a base class.

How virtual destructor works internally C++?

Inside the vtable is a list of member function pointers and a list of destructor function pointers. When a variable of any type that has a vtable goes out of scope or is deleted with delete or delete[], all of the destructor pointers in vtable the object points to are all invoked.

Does a base class need a virtual destructor?

If you are not going to delete object through a pointer to its base class – then there is no need to have a virtual destructor.

Do derived classes need virtual keyword?

No, the virtual keyword on derived classes’ virtual function overrides is not required.

What is virtual derivation example?

The virtual keyword can be used to declare virtual base classes. The following example shows the declaration of the derived class D and the base classes V , B1 , and B2 . The class B1 is both a base class and a derived class because it is derived from class V and is a base class for D : class V { /* …

Can abstract class have destructor in C++?

You can create an abstract base class with only a virtual destructor.

Can we declare base class constructor or destructor as virtual?

A virtual constructor is not possible but virtual destructor is possible. Let us experiment……. So the destruction of the base pointer (which takes an allocation on derived object!) follows the destruction rule, i.e first the Derived, then the Base.

When should a class have a virtual destructor?

Virtual keyword for destructor is necessary when you want different destructors should follow proper order while objects is being deleted through base class pointer.

When a virtual function is redefined by the derived class it is called?

Answer. (b) When a virtual function is redefined by the derived class, it is called as overriding.

What is virtual derivation in C++?

Virtual inheritance is a C++ technique that ensures that only one copy of a base class’s member variables are inherited by second-level derivatives (a.k.a. grandchild derived classes).

What is virtual derivation in C++ with example?

Does a pure virtual class need a destructor?

While defining (providing an implementation) pure virtual methods is rarely useful, you must define a pure virtual destructor. This is because the destructor of a base class is always called when a derived object is destroyed.

Do all virtual functions need to be implemented in derived classes?

Derived classes do not have to implement all virtual functions themselves. They only need to implement the pure ones. That means the Derived class in the question is correct.