presentación 2 - objetos i

8/10/2019 Presentacin 2 - Objetos I

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Objects & Classes I

Object Oriented Programming

Objects & Classes


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Agenda

How our brainmanage knowledge

Object OrientedApproach

Objects & Classes

Objects in Java

Instantiating Objects:A Closer Look


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Abstraction

Abstraction hierarchyAbstraction and software development

ow our ra n manage now e ge

Objects & Classes


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How our brain manage knowledge

Objects & Classes


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Objects & Classes

What do you remember?


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Our brains naturally

simplify the details ofall that we observe.

Objects & Classes

Details aremanageable through

a process known asabstraction.


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Process that involves recognizing and focusingon the im ortant characteristics of a situation

Abstraction

or object, and filtering out or ignoring all of theunessential details.

Objects & Classes


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Simple abstraction hierarchy

Sport car

Vehicle

Truck Car Bicycle

Focusing on a small subset of

the hierarchy is lessoverwhelming.

Objects & Classes

rules

Small

Two seat

Luxury

High speed

Sport

Lotus ElanM100

AlpineA110

PorscheBoxster


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Simple abstraction hierarchy

Objects & Classes

Correct classification


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Abstraction and software development

Developing anabstraction of the

Objects & Classes

problem is anecessary first stepof all softwaredevelopment.


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Objects & Classes

State / Data / AttributesBehavior / Operations / Methods

ec r en e pproac

Objects & Classes


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What is OOP?

The logical approach used insoftware engineering that

describes how a programminglanguage is implemented.

It is a programming paradigm where developersthink of a program as a collection of interactingobjects

Objects & Classes


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What is a object?

Merriam-Websters Collegiate Dictionary

Objects & Classes

Physical objects

Person

Student

Professor

Conceptual objects

Class

Grade

Age


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What is a software object?

State(data)

Abstraction of

Objects & Classes

Behavior(functions)

-(physical orconceptual)

object


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State is a group ofobjects attribute

values

State / Data / Attributes

Attributes aredata elements

used to describe

an object

Objects & Classes


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State / Data / Attributes

Student attributes Student state

Objects & Classes

Birth date

ID

Program

Birth date: 22/JUL/1970

ID: 649851

Program: Computer Science


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Behavior / Operations / Methods

Operations are

Objects & Classes

the things thatan object does

to modify itsattribute values

things that anobject does to

access itsattribute


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Is a list of common attributes and behaviors for

a set of similar objects.

What is a class?

Objects & Classes

Class

example

Objectsexamples


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Creating the Student Class

Attribute Typeid integer

name String

surName String

Objects & Classes

birthDate Datepapa double

advisor ???

courses ???

A class definition is like a class construction template


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Is the process by which an object is created in

memory based upon a class definition.

Instantiation

Attribute Type Value

Objects & Classes

n eger o e e erm ne

name String To be determined

surName String To be determined

birthDate Date To be determined

papa double To be determined

advisor ??? To be determined

courses ??? To be determined

Class definition


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Instantiation

Instantiation

Objects & Classes


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Encapsulation

Objects & Classes


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Encapsulation - Accessor and mutators

Objects & Classes

Accessor

Mutator


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Using Accessor and mutators

Objects & Classes


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Encapsulation benefits

hiding all the internal detail

Objects & Classes

protective barrier


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Working with reference variables

Garbage collector

Instantiating Objects: A Closer Look

Objects & Classes


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Instantiation - Working with reference variables

Objects & Classes


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Objects & Classes


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Objects & Classes


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Objects & Classes


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Objects & Classes


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Objects & Classes

I i i W ki i h f i bl


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Objects & Classes


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Where domyballoons

Objects & Classes

w go

G b ll ti


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Garbage collection

Objects & Classes


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Class activity


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1. Abstract the model to submit the grades of astudent in the SIA (Classes, behaviors, attributes,

Class activity

2. Create a Java project in NetBeans or Eclipse3. Create the Java classes of the proposed model

4. Encapsulate the classes

Objects & Classes

References


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[Barker] J. Barker, Beginning Java Objects: From Concepts To

Code, Second Edition, Apress, 2005.

[Deitel] H.M. Deitel and P.J. Deitel, Java How to Program, PrenticeHall 2007 - 7th ed.

References

[Sierra] K. Sierra and B. Bates, Head First Java, 2nd Edition,O'Reilly Media, 2005.

Objects & Classes

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