C Create Object Of Abstract Class

The c interfaces are implemented using abstract classes and these abstract classes should not be confused with data abstraction which is a concept of keeping implementation details separate from associated data.

C create object of abstract class. The main purpose of c programming is to add object orientation to the c programming language and classes are the central feature of c that supports object oriented programming and are often called user defined types. Classes inheriting an abstract class must provide definition to the pure virtual function otherwise they will also become abstract class. Why we cannot create an object for an abstract class hopefully you see now abstract classes only define the functionality the concrete class should be able to do. Classes derived from the abstract class must implement the pure virtual function or they too are abstract classes.

A class that contains at least one pure virtual function is considered an abstract class. We cannot create objects of abstract classes. A pure virtual function is declared by assigning 0 in declaration. Abstract classes act as expressions of general concepts from which more specific classes can be derived.

Abstract class and pure virtual function in c. You dont live in blue prints you live in houses that implement the blue prints. Otherwise if any member function of the base class is left undefined we will create a new abstract class this could be useful sometimes. If we wish to create a concrete class a class that can be instantiated from an abstract class we must declare and define a matching member function for each abstract member function of the base class.

Similarly we can make pure virtual functions to make the class the class abstract. Abstract class is a class which contains atleast one pure virtual function in it. In c we dont need to add an abstract keyword as the base class which has at least one pure virtual function is understood to be an abstract class. Abstract classes are used to provide an interface for its sub classes.

See the following example. An interface describes the behavior or capabilities of a c class without committing to a particular implementation of that class. The abstract class itself is only a blue print. You cannot create an object of an abstract class type.

A pure virtual function or abstract function in c is a virtual function for which we dont have implementation we only declare it. That good reason it is because an abstract base class is intended to provide interface rules to the classes that will derive from it and should not. If we want to make a class abstract in java we use the abstract keyword.