OOP-Overview - Programming Plaza

processroguishSoftware and s/w Development

Nov 18, 2013 (3 years and 8 months ago)

72 views

Florida Community College at Jacksonville

COP 2551 Object
-
Oriented Programming





Spring,2003

Object
-
Oriented Concepts

Overview


Florida Community College at Jacksonville

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Objective


Overview of Object Orientation


Object Attributes and Operations


Difference between an object and a class


3 basic Object
-
oriented principles (Encapsulation,
Inheritance and Polymorphism)


Reference: Thinking in Java (Bruce Eckel)

Free download @http://www.BruceEckel.com


2

of 10 slides

Florida Community College at Jacksonville

Overview of Object Orientation


Object orientation is a technique for system modeling, Object
oriented analysis and design, or OOAD, attempts to describe
a system as it exists in real life.


The system is modeled as a number of related
objects

that
interact. Any system needs objects to do work. It “asks” its
objects to do its work, just as you might ask objects in an
online store to deliver goods to you and charge the cost to
your credit card.


All objects have
attributes
(characteristics), this is sometimes
referred to as
state
.


They also have
operations (or methods)
, this is sometimes
referred to as
behavior
.




3

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Examples of Objects

Use an online store (such as amazon.com) as an
example, the following things may consider as
Objects:


Book


Customer


Order




4

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Object Attributes and Operations


Attributes know something (Attributes are often
data, like order ID and customer ID for an Order
object. Attributes can also be another object, such as
the entire Customer object rather than just the
customer ID.


Operations do something with what the attributes
know, (Operations can be actions that the object
does, often affecting its attributes.)


5

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Difference Between Object And
Class


A class is how you define an object. Classes are
descriptive categories or templates. Book could be a
class.


Objects are unique
instances
of classes. This Java
Certification book that costs $59.99 with item ID
62467
-
B is an
object
of the Book
class.


6

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Difference Between Object And
Class (continue)


The attributes and operations defined by a class are for its
objects, not for itself. There is no concrete realization of the
class Book, but there are Book objects, i.e. a class is a logical
construct, an object has physical reality.


A class can be compared to a blueprint. Imagine you are in
charge of building a housing development, with one housing
blueprint. Each house in a development is shaped the same
way, but some have brick or aluminum siding, some have
custom paint colors inside and some are just white, and so on
.


7

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Object
-
oriented Principle


Encapsulation


Encapsulation is the mechanism that binds together
the code and the data it manipulates, and keeps both
safe from outside interference and misuse.



8

of 10 slides

A Class

Private variables
and methods

Public variables and methods

Public variables is not recommended

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Object
-
oriented Principle
-

Inheritance


Inheritance is the process by which one object
acquires the properties of another object. By use of
inheritance, an object need only define all of its
characteristics that make it unique within its class, it
can inherit its general attributes from its parent.


9

of 10 slides

Account

Checking

Mortgage

Loan

COP 2551 Object
-
Oriented Programming



OO Concepts Overview

Florida Community College at Jacksonville

Object
-
oriented Principle


Polymorphism


Polymorphism(from Greek, meaning“many forms”)
is a feature that allows one interface to be used for a
general class of actions, i.e. one interface, multiple
methods.


Example: Account.calculateInterest()



10

of 10 slides

COP 2551 Object
-
Oriented Programming



OO Concepts Overview