CS 3050
Object
-
Oriented Analysis and
Design
Objectives
What is “Object
-
Oriented?”
Object
-
Oriented Approach Vs.
Structured Approach
How Has the Object
-
Oriented Approach
Evolved?
What are the Benefits of the Object
-
Oriented Approach?
What is “Object
-
Oriented?”
A computer system is viewed as a
collection of objects.
These objects have certain features, or
attributes.
They can also exhibit certain behaviors
Similar things can be grouped and
classified
What is “Object
-
Oriented?”
Things or objects also
interact
such as
People or other objects can interact with one
another
In building an information system, identify
the objects that are needed
We need only to know what the objects do
and use them.
Called this the building block approach
Object
-
Oriented Paradigm
Capitalize on Object Oriented Programming
(OOP)
Models Real World
Development Time Reduced
Code Reuse Easier
Class is a Representation of a System
Data
Behavior
Encapsulation provides Modularity
Other Design Methodologies
Functional Decomposition
Data Decomposition
Relational DB
Artificial Intelligence/Expert Systems
Procedural vs. OOP
Algorithmic
Main Building Block: Procedure
Functional Decomposition
Difficult to Maintain
Object
-
Oriented
Main Building Block: Class
Object is an instance of a Class
Objects has identity, state, and behavior
Procedural vs. OOP
Object
-
Oriented Approach Vs.
Structured Approach
Structured Traditional approach:
(See Fig
1.2)
Computer systems is viewed as a collection of
computer programs
Procedural approach is usually complex.
Three logic structures characterize structured
programming :
-
sequence of set of instructions
-
choice on set of instructions
-
repetition of a set of instructions.
Structured methods and rules for more
complex problems
Structured systems analysis
-
hierarchy of
procedures using
-
process model : Data Flow Diagrams
-
Data model: ER Diagrams
Structured systems design
–
organizing
smaller programs (Modular) & using
a structure chart as a guideline for modular
programming
-
hierarchy of smaller programs
Object
-
Oriented Approach Vs.
Structured Approach
Data Flow Diagrams
Entity
-
Relationship Modeling
Object Oriented Approach:
New methods, rules and concepts are
defined (
See Fig 1.1
)
Object
-
Oriented Analysis :
-
Defines all of the types of objects that are part
of the
user’s work environment
Object
-
Oriented Design:
-
Defines additional types of objects, the user
interface
and operating environment and ways in
which they
interact
Object
-
Oriented Approach Vs.
Structured Approach
Object Oriented Programming:
-
programs written that define all objects to
include their attributes and behaviors
Structured & Object Oriented
approaches are different in many ways
BUT are also similar
-
the concept of identifying business events &
defining users’ requirements
-
data modeling concepts & techniques
-
GUI & Internet Websites
Object
-
Oriented Approach Vs.
Structured Approach
How has the Object
-
Oriented
Approach Evolved?
SIMULA was first OO programming language in mid
-
sixties
Smalltalk developed by Xerox in the seventies was
instrumental in popularizing GUI interface
C++ & Pascal with OO features arose in the eighties
Object Oriented COBOL in the nineties
More recently
-
pure object Oriented Java, J++ and
VB
Current OO methods use UML (Unified Modeling
Language) to define constructs and models.
What are the Benefits of OO
OO approach addresses THREE pervasive
problems with traditional systems
development
Quality
Productivity
Flexibility
Small, small
-
contained manageable objects
reduces the complexity of the system
development
Reuse can greatly increase productivity
Adding and changing objects can be done
without interfering with the rest of the system
Enter the password to open this PDF file:
File name:
-
File size:
-
Title:
-
Author:
-
Subject:
-
Keywords:
-
Creation Date:
-
Modification Date:
-
Creator:
-
PDF Producer:
-
PDF Version:
-
Page Count:
-
Preparing document for printing…
0%
Σχόλια 0
Συνδεθείτε για να κοινοποιήσετε σχόλιο