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Listings

  • Listing 1 . Instantiating a new Radio object.
  • Listing 2 . Calling the playStation method.

Preview

Three important concepts

In order to understand OOP, you need to understand the following three concepts:

  • Encapsulation
  • Inheritance
  • Polymorphism

This module will concentrate on encapsulation. Encapsulation will be used as a springboard for a discussion of objects.

A description of an object-oriented program will be provided, along with a description of an object, and how it relates to encapsulation.

A car radio

I suspect that many of you grew up in a family where the family car contained a push-button radio and I also suspect that you learned how to operate thatradio. In fact, as children, many of you may have quarreled with your siblings about which button to push and which radio station to listen to.

In order to relate object-oriented programming to the real world, a car radio will be used to illustrate and discuss several aspects of software objects.

What you will learn

For example, you will learn that car radios, as well as software objects, have the ability to store data, along with the ability to modify or manipulatethat data.

You will learn that car radios, as well as software objects, have the ability to accept messages and to perform an action, modify their state, return a value, or some combination of the above.

You will learn some of the jargon used in OOP, including persistence, state, messages, methods, and behaviors.

You will learn where objects come from, and you will learn that a class is a set of plans that can be used to construct objects. You will learn that a Java object is an instance of a class.

You will see a little bit of Java code, used to create an object, and then to send a message to that object (call a method on the object) .

You will learn about Java references and reference variables. You will also learn a little about memory allocation for objects and variables in Java.

Discussion and sample code

Purpose of the miniseries

As mentioned earlier, I will describe and discuss the necessary and most significant aspects of OOP using Java.

The three pillars

Most books on OOP will tell you that in order to understand OOP, you need to understand the following three concepts:

  • Encapsulation
  • Inheritance
  • Polymorphism

I agree with that assessment.

Begin with encapsulation

Generally, speaking, these three concepts increase in difficulty going down the list from top to bottom. Therefore, I will begin with Encapsulation and work my way down the list in successive modules.

What is an Object-Oriented Program?

Many authors would answer this question something like the following:

An Object-Oriented Program consists of a group of cooperating objects, exchanging messages, for the purpose of achieving a common objective.

What is an object?

An object in OOP is a software construct that encapsulates data, (along with the ability to use or modify that data) , into a software entity.

What is encapsulation?

An interesting description of encapsulation was provided in an article by Rocky Lhotka regarding VB.NET. That description reads as follows:

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
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Source:  OpenStax, Accessible objected-oriented programming concepts for blind students using java. OpenStax CNX. Sep 01, 2014 Download for free at https://legacy.cnx.org/content/col11349/1.17
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