C++ Programming - OOPS Concepts - Discussion

Characteristics of Abstract Class.

1. Abstract class cannot be instantiated, but pointers and references of Abstract class type can be created.

2. Abstract class can have normal functions and variables along with a pure virtual function.

3. Abstract classes are mainly used for Up casting, so that its derived classes can use its interface.

4. Classes inheriting an Abstract Class must implement all pure virtual functions, or else they will become Abstract too.

An abstract data type is defined as a mathematical model of the data objects that make up a data type as well as the functions that operate on these objects so we can say that class is the abstract data type in other words class contains both data members as well as member function hence class is abstract data type.

An Abstract class means class which contains pure virtual function as a pure virtual function is having address zero if we try to create an object for the abstract class there is a chance to call pure virtual function which leads to segmentation fault so the object is restricted for abstract class.

Abstract class means a class which can not have any object associated with it. But it can be inherited by other classes.

A class is basically said to be abstract class when it has at least one pure virtual function.

Eg:

class A
{
public:
virtual Func()=0;
};

In the context of object-oriented programming, a class is considered an abstract data type (ADT). A class encapsulates data and functions into a single unit, allowing the user to create objects with specific properties and behaviors.

@All.

1.string is an abstract data type (ADT) because it defines data and operations without revealing implementation details.
2.class is a blueprint for creating objects and does not inherently define an abstract data type.

As per my understanding! what is use of abstract type, because we are putting some common elements & making a single element for the use of that one.

http://en.wikipedia.org/wiki/Abstract_data_type#Examples.

It says Strings is an abstract data type.

Why isn't strings given as answer then?

What is missing here? How the literal meaning of abstract and the class definition together make a new meaning? Please explain clearly.

In a class one pure virtual function is there that is call abstract class.
Pure virtual class means [virtual void add()=0;]