Chapter 4 Object Oriented Analysis Object-Oriented System Analysis and Design.
Object oriented analysis
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Transcript of Object oriented analysis
AnalysisObject-oriented
and
Design
Analysis emphasizes an investigation of the problem and requirements, rather than a solution.
Design emphasizes a conceptual solution that fulfils the requirements, rather than its implementation.
Do the right thing
Do the thing right
What is OOAD?Object-oriented analysis emphasises on finding and describing the objects—or concepts—in the problem domain.
Object-oriented design emphasises on defining software objects and how they collaborate to fulfil the requirements.
Example: Library management system
Domain Concepts
Book
title
Visualization of
Domain Concepts
Public class Book{private String title;public Chapter getChapter (int){…}
}
Representation in an object oriented programming
language
Course Layout
OOAD
Introduction to OOAD (CS212)
• Object Oriented Programming
• Modeling Language to visualize design of a system
• Repeatable solution to a commonly occurring problem
• Design and development of software
C++ UML
DPSE
Course structureOOAD
Theory
OO Concepts
Design Patterns
OO Modeling
Laboratory
C++
Marks distributionTheory
• Class participation: 5
• Mid semester 1: 15
• Mid semester 2: 20
• End semester: 60
Lab
•Each lab: 15
•Mid semester Practical: 20
•End semester Practical: 30
Lecture PlanMid sem
1Class and
ObjectOverloadin
g Inheritance
Mid sem 2
Virtual Function and
Polymorphism
Exception handling Template
End sem STL UML Design Patterns
About Lab sessions• C++ programming assignments
• Thursday – 1 PM to 3 PM - B14CS001 to B14SS017
• Friday – 1 PM to 3 PM - UG201213002 to UG201313039
• Venue: Computer centre
• 10 programming assignments, 1 mid-semester practical, 1
end-semester practical
Evaluation criteria for the lab
•Format - 2
•Documentation - 2
•Response - 4
•Design - 3
•Execution - 4
Procedural vs. Object-Oriented
Line of codeLine of codeLine of code
Data is stored independent of application
Each object is independent of the others
OO-applicationProcedural application
DATA
Main OO ConceptsEncapsulation
Abstraction
Inheritance
Polimorphism
OO Concepts
Encapsulation• Each objects methods manage it’s own attributes. • This is also known as information hiding.
• An object A can learn about the values of attributes of another object B, only by invoking the corresponding method associated to the object B.
• Example: • Class: Student• Attributes: Name, roll number• Methods: getName(), setRollNumber()
Abstraction
• A problem solving tool that allows one to think of a problem at a higher level without worrying about the details.
• Provides only essential information to the outside world and hides their background details,
• To represent the needed information in program without presenting the details.
• For example, a clock shows the time to the user, without telling how it is internally stored.
Abstraction vs. Encapsulation
Every entity that performs abstraction is encapsulated internally but every thing that shows encapsulation need not be abstraction always.
Classes• Classes are templates that have methods and attribute
names and type information packaged in a single unit
• Objects are generated by these classes and they actually contain values.
• We design an application at the class level.
• During execution objects are created by classes as they are needed to contain state information.
• Objects are removed when not needed.
Class & Objects
NameNumber
CLASS: Furniture
methods: ExampleChangeNumber
Objects:
Desk123445
ChairA32143
ChairB45687
Class Hierarchies & Inheritance• Classes can be arranged in hierarchies so that more classes
inherit attributes and methods from more abstract clases
• Class hierarchy diagrams
Class: Chair
subclasses
Chair Type A Chair Type B
Polimorphism
• One method will behave differently when it is applied to the
objects of different classes
• Different methods associated with different classes can
interpret the same message in different ways.
• Example: an object can send a message PRINT to several
objects, and each one will use it’s own PRINT method to
execute the message.
• E.g. Overloading
Unified Process
• Inception— approximate vision, business case, scope, vague
estimates.
• Elaboration— refined vision, iterative implementation of the
core architecture, resolution of high risks, identification of most
requirements and scope, more realistic estimates.
• Construction— iterative implementation of the remaining
lower risk and easier elements, and preparation for deployment.
• Transition— beta tests, deployment.
Schedule-oriented terms in the Unified Process
Inception Elaboration Construction Transition
Iteration Phase
Milestone ReleaseFinal Product