OOPOOPObject Oriented ProgrammingObject Oriented Programming

By : Tauseef Ahmad (107)

Evolution of OOPEvolution of OOP

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Machine LanguageAssembly LanguageProcedure-Oriented

Object-Oriented Programming

Procedure-OrientedProcedure-Oriented

• The primary focus is on functions.

• It basically consist of list of instructions for computer to follow, and to organize these instructions into groups known as functions.

Structure of POPStructure of POP[Procedure oriented programming][Procedure oriented programming]

Main Program

Function-1 Function-2 Function-3

Function-4 Function-5

Function-6 Function-7 Function-8

Drawbacks of POPDrawbacks of POP• Most of the function share global data.

• It does not model real world problem very well.

Global data Global data

Function-1 Function-1 Function-1

Local Data Local Data Local Data

Object-Oriented Object-Oriented LanguagesLanguages

• Object-oriented programming is not the right of any particular language.

• Like structured programming, OOP concept can be implemented using any language like C and Pascal.

Object-Oriented Object-Oriented ParadigmParadigm

• Object-oriented programming (OOP) is a programming paradigm that uses "Objects" and their interactions to design applications and computer programs.

• Everything around us are objects interacting with each others.

• Each object has a set of features, including adjectives and verbs.

• Object-oriented paradigms is sometimes thought to be a simulation of the real-world around us, which make it the paradigm of choice for most application domains: GUIs, games, business, etc.

Basic concepts of OOPBasic concepts of OOP• Objects• Classes• Data Abstraction and Encapsulation• Inheritance• Polymorphism• Dynamic Binding• Message Passing

ObjectsObjects• Objects are the run-time entities.• It may represent a person, a place, a bank

account, a table of data or any item.• Objects take up space in the memory and have

an associated address like a structure in c.• Some examples : car, man, woman etc

ClassesClasses• A class is an abstract definition of an object.

• Defines how would the object look like when created.

• Think of classes like the patents of actual inventions.

EncapsulationEncapsulation• Wrapping up of data and functions into a single

unit is known as Encapsulation.• Encapsulation is hiding the functional details from

the object calling it.• Can you drive a car?

o Yes, I can!

• So, how does acceleration work?o Huh?

• Details encapsulated (hidden) from the driver.

Data AbstractionData Abstraction• Abstraction refers to the act of representing

essential features without including the background details or explanation.

• An abstraction is a form of representation that includes only what is useful or interesting from a particular viewpoint.

• Example : A map is an abstract representation, since no map shows every detail of the territory it covers

InheritanceInheritance• Inheritance is the process by which objects of one

class acquire the properties of objects of another class.

namephoneNumberaddresshourlyWage

WageContract()CalculateTax()PayTuition()DropCourse()

Professor

namephoneNumberaddresssalary

TeachCourse()CalculateTax()DevelopCourse()

OR

Employee

namephoneNumberaddress

CalculateTax()

SupportStaff Professor

TeachCourse()DevelopCourse()

salary

Subclasses

WageContract()

hourlyWage

SupportStaff

InheritanceInheritance

Man

Suzuki

WomanBMW

Car Human

PolymorphismPolymorphismint add(int a, int b, int c){

return (a+b+c); It will return addition} of 3 integer numbersint add(int a,int b){

return (a+b); It will return addition} of 2 integer numbersfloat add(float a, float b, float c){

return (a+b+c); It will return addition} of 3 float numbers

PolymorphismPolymorphism• Polymorphism is a Greek term means the ability

to take more than one form.

Shape

Draw()

Circle Object

Draw (circle)

Box Object

Draw (box)

Triangle Object

Draw (triangle)

Message PassingMessage Passing• The process by which an object:

o Sends data to another object.o Asks the other object to invoke a method.

• In other words, objects talk to each others via messages.

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Object and Their Object and Their InteractionInteraction

Program

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Object and Their Object and Their InteractionInteraction

Program

Tom, hold your sweep!

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Object and Their Object and Their InteractionInteraction

Program

Tom, hold your sweep!

Tom, beat jerry!

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Object and Their Object and Their InteractionInteraction

Program

Tom.holdYourSweep()

Tom.BeatJerry()

IN PROGRAMMING

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Object and Their Object and Their InteractionInteraction

Program

Tom.holdYourSweep()

Tom.BeatJerry()

IN PROGRAMMING

message

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Object and Their Object and Their InteractionInteraction

Program

Tom.holdYourSweep()

Tom.BeatJerry()

IN PROGRAMMING

message

message