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How do you make a base class an abstract base class?
You create an abstract class by declaring at least one pure virtual member function. That’s a virtual function declared by using the pure specifier ( = 0 ) syntax. Classes derived from the abstract class must implement the pure virtual function or they, too, are abstract classes.
What is abstract base class in C++?
An abstract class is a class that is designed to be specifically used as a base class. An abstract class contains at least one pure virtual function. You declare a pure virtual function by using a pure specifier ( = 0 ) in the declaration of a virtual member function in the class declaration.
How does an abstract class become a base class?
It is assigned to 0, which means it has nobody, and nothing is implemented inside the function. Thus, the base class has become an abstract class as it has a pure virtual function. Initially, when the Derived_Class is derived from the base class, it also becomes an abstract class.
How is an abstract class declared in C + +?
A pure virtual function called sample_func () is declared in the base class. It is assigned to 0, which means it has nobody, and nothing is implemented inside the function. Thus, the base class has become an abstract class as it has a pure virtual function.
Can a destructor be declared in an abstract class?
This pointer can be used to call the derived class function. An abstract class can have a constructor similar to normal class implementation. In the case of the destructor, we can declare a pure virtual destructor. It is important to have a destructor to delete the memory allocated for the class.
Can a pointer be created for an abstract class?
Here we will get an error as an object cannot be created for the abstract class. Instead, the 2 nd and 3 rd line of code can be implemented, a pointer can be created and can be used to call derived class function.