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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.
Should base class have virtual destructor?
Any class that is inherited publicly, polymorphic or not, should have a virtual destructor. To put another way, if it can be pointed to by a base class pointer, its base class should have a virtual destructor.
Can derived class access private members of base class?
Derived class can not access the private members of it’s base class. No type of inheritance allows access to private members.
Can a derived class destructor invoke base class destructor?
Yes, the Base class destructor is automatically invoked after the Derived class Destructor, irrespective of Derived class destructor being explicitly defined or not.
Does base class destructor get called?
No, destructors are called automatically in the reverse order of construction. (Base classes last). Do not call base class destructors. you can’t have a pure virtual destructor without a body.
What happens if destructor is not virtual?
Deleting a class without a virtual destructor will only call the destructor of the type of the pointer being deleted. This can cause a defect if the pointer type is a base type while the object instance is a derived type.
Are destructors always virtual?
Destructors are not always declared virtual . A virtual destructor is important if a class is intended to be used as a public base class.
Are destructors inherited?
Destructors are not inherited. If a class doesn’t define one, the compiler generates one. Inheritance is what : mechanism of reusing and extending existing classes without modifying them, thus producing hierarchical relationships between them. Inheritance is almost like embedding an object into a class.
When to call the Destructor on a derived class?
The destructor on the base class must be called in order for it to release its resources. Rule of thumb is that a derived class should only clean up its own resources and leave the base class to clean up itself.
Is there a non virtual destructor for derived?
Not really; a non-virtual destructor signifies that deleting an instance of derived via a base pointer will not work. For example: class Base {}; class Derived : public Base {}; Base* b = new Derived; delete b; // Does not call Derived’s destructor! If you don’t do delete in the above manner, then it will be fine.
When to call base class destructor in polymorphism?
Your base class destructor will always be automatically called upon deletion of the derived instance since destructors don’t take parameters. If you’re using polymorphism and your derived instance is pointed to by a base class pointer, then the derived class destructor is only called if the base destructor is virtual.
When to call the base virtual destructor in C + +?
Destructors in C++ automatically gets called in the order of their constructions (Derived then Base) only when the Base class destructor is declared virtual. If not, then only the base class destructor is invoked at the time of object deletion. Example: Without virtual Destructor