© Wolfgang Pelz 2001-04Introduction Object-Oriented Methods: Analysis, Design & Programming Dr....

© Wolfgang Pelz 2001-04

Introduction

Object-Oriented Methods:Analysis, Design &

Programming

Dr. Wolfgang PelzDr. Yingcai Xiao

The University of Akron

© Wolfgang Pelz 2001-04Introduction 2

Outline

• OOA

• OOD: UML

• OOP: C++


OOA - OOD - OOPHenderson

Analysis

Design

Implementation

Coad/Nicola

“Baseball Model”


Outline

• Software Development Models

• Object-Oriented Concepts

• Introduction to C

• UML


UML Bibliography

• The Unified Modeling Language User Guide Booch et al, Addison-Wesley

• UML Toolkit Hans-Erik Eriksson et al, Wiley

• UML in a Nutshell Sinan Si Alhir, O’Reilly


General Bibliography

• Design Patterns Erich Gamma et al, Addison-Wesley

• Applying UML and Patterns Craig Larman, Prentice-Hall

• The Practice of Programming Brian Kernighan et al, Addison-Wesley


C++ References• “C++ for Java Programmers”

Mark Allen Weiss, Pearson / Prentice Hall• “C++: How to Program",

Deitel & Deitel, Prentice Hall• "C++ Primer”

Stanley Lippman, Addison-Wesley• "The C++ Programming Language"

Bjarne Stroustrup, Addison-Wesley• "The Annotated C++ Reference Manual“

Bjarne Stroustrup and Margareth Ellis, Addison Wesley


The Spiral Software Cycle

Traditional


The Spiral Software Cycle

Object-Oriented


The Large Picture

• Hardware Engineering: automated mass production of standard components.

• Software Engineering: treat software development as an engineering process.

• CASE : Computer-Aided Software Engineering• CASE Tools: Automation of Software Development• The fundamental software component is an object.• An important goal of OO is code reuse.


The Large Picture

Design Reuse =>

Computer Science

The study of the theoretical foundations of information and computation and their implementation and application in computer systems.

(http://en.wikipedia.org/wiki/Computer_science)

Computer Science = Data + Data Manipulation

Programming = Data Structures + Algorithms

Code Reuse of algorithms and data structures.

Design Patterns

http://en.wikipedia.org/wiki/Information

http://en.wikipedia.org/wiki/Computation

http://en.wikipedia.org/wiki/Computer_system


Objects• concepts, concrete or abstract, with meaning

derived from the problem domain “the real world”

• promote an understanding of the problem domain

• provide a basis for implementation

• encapsulation of state (data values) and behavior (operations)


Objects (cont.)• Exhibit behavior by invoking a method in

response to a message

• instances of classes

• an object-oriented program is a collection of autonomous interacting and collaborating objects


Classes

• objects sharing common characteristics

• dictate the behavior of the object

• contain– state: attributes, fields, variables, data member– behavior: functions, methods, function member

• access specifiers

• instantiation

• abstract versus concrete


3 Pillars of Object-Orientation• encapsulation

• inheritance

• polymorphism


Encapsulation• combination of state and behavior

• implementation details are hidden internally

• internal mechanisms can change while public interfaces remain stable

• state may be retrieved using public methods

• behavior consists of methods activated by receipt of messages


Inheritance• organization of classes into a hierarchical

inheritance tree• data and behavior associated with classes higher

in the tree are accessible to those classes lower in the tree

• terminology– ancestor/descendant– superclass/subclass– generalization/specialization


Single Inheritance• classes/objects inherit from only one parent

• no ambiguity due to name clashes

• examples: Java, Smalltalk


Multiple Inheritance• classes/objects may have more than one

parent

• ambiguity (name clashes) can occur

• allows abstract classes to be more specific in characteristics (kitchen sink problem)

• examples: C++, Eiffel


Inheritance Diagram


Another Inheritance Diagram


Inheritance for Teaching Assistant

• birthday

• library privileges


Polymorphism• polymorphism: many forms

• localizes responsibility for behavior

• object automatically uses correct implementation for a method

• many objects can respond to the same message

• minimizes interface parameter passing


Polymorphism• determination of method is done at:

– run-time: dynamic binding, late binding– compile-time: static binding, early binding

• treat many types (all derived from the same type) as if they were all one type

• single piece of interface works on all these types


Polymorphism Example


3 Pillars of Object-Orientation• Encapsulation

Combine data structures and algorithm together and insulate internal code and data from their interface. Easily to be reused.

• InheritanceReuse the code of the parents as is.

• PolymorphismObjects of similar type have the same interface. Easily to be reused.


Relationships• is-a: code reuse through inheritance

– instances of a subclass must be more specialized forms of the superclass

– instances of a subclass can be used where quantities of the superclass are expected

• has-a: code reuse through inclusion – component or contains– instances of a class possess fields of a given

type


OOA: Objects & Methods• write description of problem domain• nouns are candidates for objects• verbs are candidates for methods• designs are implementation-language independent• UML can be used to depict the designs

© Wolfgang Pelz 2001-04Introduction Object-Oriented Methods: Analysis, Design & Programming Dr....

Documents

Transcript of © Wolfgang Pelz 2001-04Introduction Object-Oriented Methods: Analysis, Design & Programming Dr....