1. Basic Object Oriented Approach
Shaik Khaja Hussain,
Assistant Professor in Computer Science

2. SHAIK KHAJA HUSSAIN Basic Object Oriented Approach
Object Oriented Programming
Computer Science
2nd Semester - M.Sc.(Computer Science)
National P.G. College – Rayalaseema University, Kurnool

3. Session Objectives Discuss the programming Paradigms
Discuss the Object Oriented Approach
Discuss basic Object-Oriented concepts
Object
Class
Encapsulation
Abstraction
Polymorphism
Inheritance

4. Programming Paradigms
Unstructured Programming
Procedural Programming
Structural Programming
Object Oriented Programming

5. Unstructured Programming
In this whole problem is solved as a single block.
All the data are global and there is no security.
To share the codes jumps are allowed and so contain lot of goto statements.
This is suitable only for small problem.
Difficult to follow and correct errors
Eg, Assembly Language, BASIC.

6. Procedural Programming
Program is divided in to a number of sub programs.
Reusability of procedures/functions.
The program has global and local variables.

7. Structural Programming
The program is divided into modules and the modules are then divided into functions.
Each module can work independent of one another.

8. Object Oriented Programming
The Program is divided into number of small units called Object. The data and function are build around these objects.
The data of the objects can be accessed only by the methods associated with that object.
The methods of one object can access the methods of other object.

9. The Object-Oriented Approach
The object-oriented approach is quite comparable to the way a human solves daily problems.
The approach consists of identifying objects and how to use these objects in the appropriate order to solve the problem.
There are four steps in the object oriented methodology. They are
Identify the problem.
Identify the objects needed for the solution.
Identify the messages to be sent to the objects.
Create a sequence of messages to the objects that solve problem.

10. Object – Oriented Programming
Here the application has to implement the entities as they are seen in real life and associate their actions and attributes with each other.
Accounts
Functions
Calculate salary
Pay salary
Pay bills
Tally accounts
Transact with banks
Data
Employee details
Salary statements
Bills
Vouchers
Receipts

11. Objects
An object is a concept or thing with defined boundaries that is relevant to the problem we are dealing with.
Some real-life entities :
Physical Objects
Vehicles in a traffic -monitoring application
Electrical components in a circuit design problem
Elements of the computer-user environment
Windows
Menus

12. Objects (contd…) Objects should have two things Model : Ferrari
Properties
Behaviour
Model : Ferrari
Color : Red
Year : 1995
Actions
Start
Stop
Accelerate

13. Classes
A class is a group of objects that have the same properties, common behavior.
Polygon objects
Polygon class
Properties
Vertices
Border color
Fill color
Methods
Draw
Erase
Move

14. Encapsulation
The wrapping up of data and methods into a single unit is called as Encapsulation.
Encapsulation is a process that allows selective hiding of properties and methods in a class.
Attributes
methods
Class

15. Abstraction
Abstraction is the process of hiding the details and exposing only the essential features of a particular concept or object.
Class
Data Abstraction
Procedural Abstraction
private
Data/methods
Not accessible from outside class
public
Data/methods
Accessible from outside class

16. Polymorphism
Polymorphism allows same method to behave differently on different classes.
Allows one interface to be used for general class of actions
Sub classes
Class : Shape
Methods :
Draw
Move
Initialize

17. Inheritance
Inheritance is the property that allows the reuse of an existing class to build a new class
Objects of one class acquire the properties of objects of another class
Provides the idea of reusability
Animals

18. Reusability Make sounds Eat and drink Felines Hunt prey Roar Mew
Eat flesh
Hunt big game
Mew
Drink milk
Hunt mice

19. Object – Oriented Languages
Small Talk
Eiffel
CLOS
Java