Object Oriented Programming

• Object Oriented Programming(OOP) is a programming  technique on which programs are written on the basis of objects.
• An Object is a collection of data and functions.
• Object may represent a person, thing, or place in real world.
• In OOP, data and all possible functions on data are grouped together.
• Object-Oriented Programs are easier to learn and modify.
• Object Oriented Programming is powerful technique to develop software. It is used to analyze and design the application in terms of objects.
• It deals with data and procedures that process the data as a single object.
• Some of the object-oriented languages that have been develped are:
  • C++
  • Smalltalk
  • Eiffel
  • CLOS
  • Java

Features Of OOP

Following are the features of OOP

1. Objects
2. Real-world Modelling
3. Reusability
4. Information Hiding

Real-World Modelling

• OOP is based on real-world modeling.
• As in real world, things have properties and working capabilities. Similarly, objects have data and functions.
• Data represents properties and
• Functions represents working of objects.

Reusability

• OOP provides ways of reusing the data and code.
• Inheritance is a technique that allows a programmer to use the code of existing program to create new program.

Information Hiding

• OOP allows the programmer to hide important data from the user, it is performed by encapsulation.

Polymorphism

• Polymorphism is an ability of an object to behave in multiple ways.

Objects

• An Object represent an entity in the real world such as person, things or concept etc.
• An object is defined by its name.
• An object consist of the following two things:
  • Properties: Properties are the characteristics of an object.
  • Functions: Functions are the actions that can be performed by an object.

Examples:

Some examples of different types are as follows:

• • Physical Objects
    • Vehicles such as car, bus truck etc.
    • Electrical Components
  • Elements of Computer User Environment
    • Windows
    • Menus Graphic Objects
    • Mouse and Keyboard
  • User Defined Data Types
    • Time
    • Angles

Properties Of Objects

• The characteristics of an objects are known as its properties or attributes.
• Each Object has its own properties. These properties can be used to describe the object.

         Example:

• • The properties of an object Person can be follows:
    • Name
    • Age 
    • Height
  • The properties of an object Car can be follows:
    • Color
    • Price
    • Model
    • Engine Power

• The set of values of the attributes of a particular object is called its state. It means that the state of object can be determined by the values of its attributes.
• Following figure shows the value of the attributes of an Object Car.