Object Oriented Programming Principles

Object Oriented Programming PrinciplesObject Oriented Programming Principles

Lecturer: Lecturer: Kalamullah RamliKalamullah Ramli

Electrical Engineering Dept.Electrical Engineering Dept.University of IndonesiaUniversity of Indonesia

Session-3Session-3

Slide - Slide - 22OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Object-Oriented Object-Oriented Programming:Programming:A New Programming A New Programming Paradigm… Paradigm… What is Matlab's programming What is Matlab's programming

paradigm?paradigm? Matlab is Matlab is proceduralprocedural: the focus is on : the focus is on

the the functionsfunctions (procedures) (procedures) What is the programming paradigm What is the programming paradigm

in OOP?in OOP? As the name suggests, in OOP the As the name suggests, in OOP the

focus is onfocus is on OBJECTSOBJECTS

This doesn't say much unless we This doesn't say much unless we understand what we mean with the understand what we mean with the term term ObjectObject… So let's move on.… So let's move on.

Slide - Slide - 33OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Objects Combine Properties & Objects Combine Properties & Behavior Behavior [1/2][1/2]

Remember following Structures:Remember following Structures: person.firstname = 'John'; person.lastname = 'Leonard'; person.address1 = '803 Shallowford Lane';

person.city = 'Peachtree City'; person.state = 'GA'; person.zip = '30269-4289';

A structure contains data in an organized A structure contains data in an organized fashion.fashion.

Slide - Slide - 44OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Objects Combine Properties & Objects Combine Properties & Behavior Behavior [2/2][2/2]

If we add functions or If we add functions or methodsmethods to a to a structure, it becomes an object:structure, it becomes an object:

person.print_address(); person.set_lastName('Paredis');

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More Examples of Objects More Examples of Objects [1/2][1/2]

Car:Car: Properties: color, speed, fuel consumption, HP… Behaviors: start, stop, turning, …

Triangle:Triangle: Properties: area, perimeter, linestyle, location,… Behaviors: translate, rotate, shrink, flip,…

Date:Date: Properties: year, month, day, … Behaviors: setDate, getMonth, isGreater, …

Slide - Slide - 66OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

More Examples of Objects More Examples of Objects [1/2][1/2]

Properties: Properties: information about the objectinformation about the object Behaviors: Behaviors: methods to set, get and methods to set, get and

process propertiesprocess properties

Combining properties and behaviors in Combining properties and behaviors in objects is calledobjects is called

EncapsulationEncapsulation

Slide - Slide - 77OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Objects Combine Properties and Objects Combine Properties and Behavior:Behavior:So What? Why should we care? So What? Why should we care? [1/2][1/2]

Black Box PhilosophyBlack Box Philosophy:: Objects perform Objects perform

computation by making computation by making requests of each other requests of each other through the passing of through the passing of messagesmessages

The only way to interact The only way to interact with an object is through with an object is through its methods!its methods!

http://java.sun.com/docs/books/tutorial/java/concepts/object.htmlhttp://catalog.com/softinfo/objects.html

Messages

Code

Data

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Objects Combine Properties and Objects Combine Properties and Behavior:Behavior:So What? Why should we care? So What? Why should we care? [2/2][2/2]

This is called This is called Information HidingInformation Hiding (the data is hidden from the (the data is hidden from the

user)user)

The collection of all methods is The collection of all methods is called thecalled the interface interface of the objectof the object

http://java.sun.com/docs/books/tutorial/java/concepts/object.htmlhttp://catalog.com/softinfo/objects.html

Slide - Slide - 99OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Encapsulation and Data Hiding Encapsulation and Data Hiding [1/2][1/2]

Properties Properties (Variables)(Variables) Speed RPM Current Gear

Methods (Functions)Methods (Functions) Braking Acceleration Turn Changing Gears

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Encapsulation and Data Hiding Encapsulation and Data Hiding [2/2][2/2]

These methods are independent of These methods are independent of how the bicycle has been built how the bicycle has been built (hides the implementation)(hides the implementation)

You can control access to members You can control access to members of an objectof an object

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Working with Objects: Working with Objects: Messages Messages [1/2][1/2]

Objects perform computation by Objects perform computation by making requests of each other through making requests of each other through the passing of messages the passing of messages

Parts of a message –Parts of a message – The object to which the message is addressed The name of the method to perform Any parameters needed by the method\

Slide - Slide - 1212OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Working with Objects: Working with Objects: Messages Messages [2/2][2/2]

Different objects may respond differently Different objects may respond differently to an identical message:to an identical message: bicycle.changeGears(lowerGear) car.changeGears(lowerGear)

The same name and the same argument, The same name and the same argument, but a different method = but a different method = POLYMORPHISMPOLYMORPHISM

A method is defined only in the scope of A method is defined only in the scope of a particular type of object, called classa particular type of object, called class

Polymorphism is also called: Polymorphism is also called: function function overloadingoverloading

Slide - Slide - 1313OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Class and Object Class and Object [1/2][1/2]

Now that we know what an object is all Now that we know what an object is all about, let's look at how we can about, let's look at how we can organizeorganize these objects these objects

Class =Class = A blueprint, or prototype, that A blueprint, or prototype, that defines the variables and the methods defines the variables and the methods common to all objects of a certain kindcommon to all objects of a certain kind

Objects are individual instances of a class

Slide - Slide - 1414OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Class and Object Class and Object [2/2][2/2]

House Plans:House Plans:the architectural drawings the architectural drawings that describe how a house that describe how a house is to be constructedis to be constructed

A House:A House:

The house built from the The house built from the plans is an instance of the plans is an instance of the House Class. The process House Class. The process of building the house is of building the house is called called InstantiationInstantiation

Slide - Slide - 1515OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Organizing Objects: Inheritance Organizing Objects: Inheritance [1/2][1/2]

Super class(parent)

Sub class(child)

Children inherit• properties• behaviors

Slide - Slide - 1616OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Organizing Objects: Inheritance Organizing Objects: Inheritance [2/2][2/2]

Sub classSub class (Child) (Child)• A class that is derived from a particular

class, perhaps with one or more classes in between

Super classSuper class (Parent) (Parent)• A class from which a particular class is

derived, perhaps with one or more classes in between

Inheritance promotesInheritance promotes Reuse of code Better Management of code

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Abstraction in OOP Abstraction in OOP [1/2][1/2]

Abstractions Abstractions reveal causes and effects, reveal causes and effects, expose patterns and frameworks and expose patterns and frameworks and separate what's important from what's notseparate what's important from what's not

Abstraction in programmingAbstraction in programming helps you helps you make your ideas concrete in your code make your ideas concrete in your code without obscuring the architecture with without obscuring the architecture with detailsdetails

In procedural languages:In procedural languages: structures and functions are abstractions

Slide - Slide - 1818OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Abstraction in OOP Abstraction in OOP [2/2][2/2]

OOP takes abstraction one step further OOP takes abstraction one step further through:through:

encapsulationencapsulation data hidingdata hiding polymorphismpolymorphism InheritanceInheritance

Slide - Slide - 1919OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Object-Oriented Programming Object-Oriented Programming [1/2][1/2]

A Quick Review:A Quick Review: ““OOP is more a way of thinking than just a OOP is more a way of thinking than just a

programming technique” – “programming technique” – “conceptual tool that you conceptual tool that you use in thinking how to solve a problem”use in thinking how to solve a problem”

Computer Computer objectsobjects form the basis form the basis Objects treated as real life objectsObjects treated as real life objects

Identities Properties Behaviors

Data and functionality Data and functionality encapsulatedencapsulated in an object in an object Data Data hiddenhidden behind methods behind methods

Slide - Slide - 2020OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Object-Oriented Programming Object-Oriented Programming [2/2][2/2]

Objects organized in class hierarchies: inheritanceObjects organized in class hierarchies: inheritance Objects interact through messages – methodsObjects interact through messages – methods Polymorphism: the same message has a different Polymorphism: the same message has a different

meaning for different objectsmeaning for different objects

Slide - Slide - 2121OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Benefits of Object Oriented Benefits of Object Oriented ProgrammingProgramming

Analysis and Design made easierAnalysis and Design made easier Understanding of code made easierUnderstanding of code made easier Code ReuseCode Reuse Ease of maintenance and enhancement Ease of maintenance and enhancement Simplifies collaborationSimplifies collaboration Fewer and shorter design iterationsFewer and shorter design iterations

Slide - Slide - 2222OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

Examples of Programming Examples of Programming LanguagesLanguages Procedural languagesProcedural languages

C FORTRAN BASIC Pascal

Object Oriented languagesObject Oriented languages C++ Smalltalk Java

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Assignment#2a: OOP vs Procedural Assignment#2a: OOP vs Procedural ProgrammingProgramming

Object-OrientedObject-Oriented

ProceduralProcedural

Due date: Due date: Friday, February 27Friday, February 27thth, 2004, 2004

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Assignment#2b: Object Oriented Assignment#2b: Object Oriented PhilosophyPhilosophy

““Simulate the functionality of your computer Simulate the functionality of your computer using the object oriented using the object oriented philosophyphilosophy” ”

Draw a diagram of the components present in Draw a diagram of the components present in the computer. What is the flow of information the computer. What is the flow of information between these components? Leverage from between these components? Leverage from previous lectures.previous lectures.

Identify the classes and objects that you Identify the classes and objects that you would need to simulate these components. would need to simulate these components. How do these classes interact?How do these classes interact?

Identify the variables and methods that you Identify the variables and methods that you would assign to each class.would assign to each class.

Due Date: Due Date: Friday, March 5Friday, March 5thth, 2004, 2004

Slide - Slide - 2525OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

References and Additional References and Additional ReadingReading

““Object Oriented Programming, ” Object Oriented Programming, ” http://www.toodarkpark.net/computers/objchttp://www.toodarkpark.net/computers/objc/oop.html/oop.html

““Core Java, ” Cay S. Horstmann and Gary Core Java, ” Cay S. Horstmann and Gary Cornell, Cornell, Sun MicrosystemsSun Microsystems

““ Thinking in C++Thinking in C++, , ”” Bruce Eckel, Bruce Eckel, http://www.mindview.net/Books/TICPP/Thinhttp://www.mindview.net/Books/TICPP/ThinkingInCPP2e.htmlkingInCPP2e.html

“ “ Introduction to Object Oriented Introduction to Object Oriented Programming, ” Timothy Budd, Programming, ” Timothy Budd, ftp://ftp.cs.orst.edu/pub/budd/oopintro/3rdEftp://ftp.cs.orst.edu/pub/budd/oopintro/3rdEdition/info.htmldition/info.html

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ClosureClosure

LearningLearning Object oriented programming is more a philosophy than Object oriented programming is more a philosophy than

mere technique to develop programs…mere technique to develop programs… This philosophy provides modularity to programsThis philosophy provides modularity to programs Modularity provides openness to change…Modularity provides openness to change… Enables developing complex systemsEnables developing complex systems

Food for ThoughtFood for Thought How will object oriented philosophy help in the future of How will object oriented philosophy help in the future of

software development?software development? How can the object oriented philosophy based on How can the object oriented philosophy based on

modularity be used in your field of specialization?modularity be used in your field of specialization? What changes are required to adapt this philosophy to What changes are required to adapt this philosophy to

your field?your field?

Slide - Slide - 2727OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, OOP Lecture 2004 Dr. –Ing. Ir. Kalamullah Ramli, M.EngM.Eng

The EndThe End

QUESTIONS & QUESTIONS & COMMENTS ?COMMENTS ?