Object Oriented Programming

Object Oriented ProgrammingBinnur Kurtkurt@ce.itu.edu.trIstanbul Technical UniversityComputer Engineering DepartmentObject Oriented Programming1Version 0.1.2

AboutAbout thethe LecturerLecturer BScİTÜ, Computer Engineering Department, 1995 MScİTÜ, Computer Engineering Department, 1997 Areas of Interest¾Digital Image and Video Analysis and Processing¾Real-Time Computer Vision Systems¾Multimedia: Indexing and Retrieval¾Software Engineering¾OO Analysis and Design2

WelcomeWelcome toto thethe CourseCourse Important Course Information¾ Course Hours 10:00-13:00 Thursday¾ Course Web Page http://www.cs.itu.edu.tr/ kurt/courses/blg252e¾ Join to the group http://groups.yahoo.com/group/blg252e blg252e@yahoogroups.com¾ E-mail3

GradingGrading SchemeScheme¾ 3 Homeworks (5% each)¾ 2 Midterm Exams (20%,25%)¾ A final exam (40%)¾ You must follow the official Homework .html).¾ Academic dishonesty including but not limited to cheating,plagiarism, collaboration is unacceptable and subject to disciplinaryactions. Any student found guilty will have grade F. Assignmentsare due in class on the due date. Late assignments will generally notbe accepted. Any exception must be approved. Approved lateassignments are subject to a grade penalty.4

ReferencesReferencesThe presentation is based onAsst.Prof.Dr. Feza Buzlaca’s Lecture Notes5

Tell me and I forget.Show me and I remember.Let me do and I understand.—Chinese ProverbThere is no time for lab sessionsOn the course web page you will find lab files for eachweek. You should do the lab sessions on your own.Just follow the instructions on these documents.Object Oriented Programming6

PurposePurpose ofof thethe CourseCourse To introduce several programming paradigms including ObjectOriented Programming, Generic Programming, DesignPatterns To show how to use these programming schemes with the C programming language to build “good” programs.Object Oriented Programming7

CourseCourse OutlineOutline1. Introduction to Object Oriented Programming.2. C : A Better C.3. Classes and Objects4. Constructors and Destructors5. Operator Overloading6. Inheritance7. Pointers to Objects8. Polymorphism9. ExceptionsObject Oriented Programming8

CourseCourse OutlineOutline10. Templates11.The Standard Template Library - STLObject Oriented Programming9

HowHow toto UseUse thethe IconsIconsDemonstrationReferenceObject Oriented ProgrammingDiscussionExercise10

1 INTRODUCTION11

ContentContentIntroduction 1 Introduction to Software Engineering Object-Oriented Programming ParadigmObject Oriented Programming12

Introduction 1SoftwareSoftware Computer Software is the product that software engineersdesign and build. It encompasses– programs that execute within a computer of any size andarchitecture,– documents that encompass hard-copy and virtual forms,– data that combine numbers and text but also includesrepresentations of pictorial, video and audio information.Object Oriented Programming13

Introduction 1HistoryHistory Common problems:– Why does it take so long?– Why are development costs so high?– Why can’t find all faults before delivery?– Why can’t we measure the development?Object Oriented Programming14

Introduction 1HistoryHistory Software Engineering: 1967, NATO Study Group,Garmisch/GERMANY 1968, NATO Software Engineering Conference:Software Crisis– Low quality– Not met deadlines and cost limitsObject Oriented Programming15

AfterAfter 3535 yearsyearsIntroduction 1 Still softwares are– Late– Over budget– With residual faults Means– SW has own unique properties and problems– Crisis DepressionObject Oriented Programming16

IsIs SWSW AnAn Engineering?Engineering?Introduction 1 May be? Bridge – Operating System–––––After collapse, redesign & rebuildInspect similar bridgesPerfectly engineeredExperienceMaintainingObject Oriented Programming17

Introduction 1McCallMcCall QualityQuality ityP R O D U C T R E V IS I O NPortabilityReusabilityInteroperabilityPRODUCT TRANSITIONPRODUCT liabilityObject Oriented Programming18

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Introduction 1McCallMcCall QualityQuality TriangleTriangle Correctness: The extent to which a program satisfies itsspecification and fulfills the customer’s mission objectives Reliability: The extent to which a program can be expected toperform its intended function with required precision Efficiency: The amount of computing resources and coderequired by a program to perform its function Integrity: Extent to which access to software or data byunauthorized persons can be controlled Usability: Effort required to learn, operate, prepare input andinterpret output of a program Maintainability: Effort required to locate and fix an error in aprogramObject Oriented Programming20

Introduction 1McCallMcCall QualityQuality TriangleTriangle Flexibility: Effort required to modify an operational program Testability: Effort required to test a program to ensure that itperforms its intended function Portability: Effort required to transfer the program from onehardware and/or software system environment to another Reusability: Extent to which a program can be reused in otherapplications Interoperability: Effort required to couple one system to anotherObject Oriented Programming21

Introduction ect Oriented Programming22

Introduction 1DevelopmentDevelopment TeamTeamObject Oriented Programming23

Introduction 1SoftwareSoftware LifeLife CycleCycle Requirements Phase Specification Phase Design Phase Implementation Phase Integration Phase Maintenance Phase Retirement PhaseObject Oriented Programming24

RequirementsRequirements PhasePhaseIntroduction 1 Defining constraints– Functions– Due dates– Costs– Reliability– Size Types– Functional– Non-FunctionalObject Oriented Programming25

SpecificationSpecification PhasePhaseIntroduction 1 Documentation of requirements– Inputs & Outputs– Formal– Understandable for user & developer– Usually functional requirements. (what to do)– Base for testing & maintenance The contract between customer & developer ?Object Oriented Programming26

Introduction 1DesignDesign PhasePhase Defining Internal structure (how to do) Has some levels (or types of docs)– Architectural design– Detailed design– . Important– To backtrack the aims of decisions– To easily maintainObject Oriented Programming27

Introduction 1ImplementationImplementation PhasePhase Simply coding Unit tests– For verificationObject Oriented Programming28

Introduction 1IntegrationIntegration PhasePhase Combining modules System tests– For validation Quality testsObject Oriented Programming29

Introduction 1MaintenanceMaintenance PhasePhase Corrective Enhancement– Perfective– Adaptive Usually maintainers are not the same people withdevelopers. The only input is (in general) the source code of thesoftware?!?Object Oriented Programming30

Introduction 1RetirementRetirement PhasePhase When the cost of maintenance is not effective.– Changes are so drastic, that the software should beredesigned.– So many changes may have been made.– The update frequency of docs is not enough.– The hardware (or OS) will be changed.Object Oriented Programming31

Introduction 1WhyWhy ObjectObject Technology?Technology? Expectations are, Reducing the effort, complexity, and cost of developmentand maintenance of software systems. Reducing the time to adapt an existing system (quickerreaction to changes in the business environment).Flexibility, reusability. Increasing the reliability of the system.Object Oriented Programming32

Introduction 1WhyWhy C C C supports writing high quality programs (supports OO) C is used by hundreds of thousands of programmers in everyapplication domain.– This use is supported by hundreds of libraries, hundreds oftextbooks, several technical journals, many conferences. Application domain:– Systems programming: Operating systems, device drivers. Here,direct manipulation of hardware under real-time constraints areimportant.– Banking, trading, insurance: Maintainability, ease of extension,ease of testing and reliability is important.– Graphics and user interface programs– Computer Communication ProgramsObject Oriented Programming33

Introduction 1WhatWhat isis Programming?Programming? Like any human language, a programming languageprovides a way to express concepts. Program development involves creating models of realworld situations and building computer programs based onthese models. Computer programs describe the method of implementingthe model. Computer programs may contain computer worldrepresentations of the things that constitute the solutionsof real world problems.Object Oriented Programming34

WhatWhat isis Programming?Programming? (Con’t)(Con’t)Introduction 1Programming Languageclass {}ObjectAbstraction/ModelingImplementationObject ObjectREAL WORLDPROGRAMMERCOMPUTER If successful, this medium of expression (the object-oriented way)will be significantly easier, more flexible, and efficient than thealternatives as problems grow larger and more complex.Object Oriented Programming35

Introduction 1LearningLearning C C Like human languages, programming languages also have many syntaxand grammar rules. Knowledge about grammar rules of a programming language is notenough to write “good” programs. The most important thing to do when learning C is to focus onconcepts and not get lost in language-technical details. Design techniques is far more important than an understanding ofdetails; that understanding comes with time and practice. Before the rules of the programming language, the programmingscheme must be understood. Your purpose in learning C must not be simply to learn a newsyntax for doing things the way you used to, but to learn new andbetter ways of building systemsObject Oriented Programming36

SoftwareSoftware QualityQuality MetricsMetrics A program must do its job correctly. It must be useful and usable. A program must perform as fast as necessary (Real-time constraints). A program must not waste system resources (processor time, memory, disk capacity,network capacity) too much. It must be reliable. It must be easy to update the program. A good software must have sufficient documentation (users manual).user Source code must be readable and understandable. It must be easy to maintain and update (change) the program. A program must consist of independent modules, with limited interaction. An error may not affect other parts of a program (Locality of errors). Modules of the program must be reusable in further projects. A software project must be finished before its deadline. A good software must have sufficient documentation (about development).Software developerObject-oriented programming technique enables programmers to build highquality programs. While designing and coding a program, these quality metrics37must be kept always in mind.

SoftwareSoftware DevelopmentDevelopment ProcessProcessTask/ProblemIntroduction plementationC TestObject Oriented ProgrammingProduct38

Introduction 1 Analysis: Gaining a clear understanding of the problem. Understandingrequirements. They may change during (or after) development of thesystem! Building the programming team. Design: Identifying the key concepts involved in a solution. Models ofthe key concepts are created. This stage has a strong effect on the qualityof the software. Therefore, before the coding, verification of the createdmodel must be done. Design process is connected with the programming scheme. Here, ourdesign style is object-oriented. Coding: The solution (model) is expressed in a program. Coding is connected with the programming language. In this course wewill use C . Documentation: Each phase of a software project must be clearlyexplained. A users manual should be also written. Test: the behavior of the program for possible inputs must be examined.Object Oriented Programming39