Complete Modern C++ - Abstract Class

The video tutorial explains abstract classes and pure virtual functions using a document hierarchy example. It highlights the importance of overriding the serialize function in derived classes like XML to ensure correct data serialization. The tutorial addresses issues with default implementations and demonstrates how making a function pure virtual enforces implementation in child classes. Key concepts include abstract classes, pure virtual functions, and their role in creating interfaces.

What is the main purpose of a virtual function in a base class?

• To ensure the function is always called from the base class

• To make the base class non-instantiable

• To allow child classes to provide their own implementation

• To prevent child classes from overriding it

What happens if the serialize function is not overridden in the XML class?

• The serialize function of the document class is invoked

• The XML class becomes abstract

• The XML data gets serialized correctly

• The program crashes

How can the problem of not overriding the serialize function be solved?

• By removing the serialize function from the base class

• By making the serialize function pure virtual

• By making the serialize function private

• By using a different programming language

What is a characteristic of an abstract class?

• It must have at least one pure virtual function

• It can be instantiated

• It can only have static functions

• It cannot have any data members

What is the role of a pure virtual function in an abstract class?

• To provide a default implementation for all child classes

• To ensure the derived classes do not override it

• To establish a contract for derived classes to implement

• To make the class non-abstract

What is a true interface in the context of abstract classes?

• A class with no functions

• A class with only static functions

• A class with only pure virtual functions

• A class with only data members

What happens if a derived class does not override a pure virtual function?

• The derived class becomes abstract

• The derived class can still be instantiated

• The base class becomes non-abstract

• The function is automatically overridden