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Expose the interface and hide the implementation

As in the steering mechanism for a car, a common approach in OOP is to "hide the implementation" and to "expose the interface" through encapsulation.

Inheritance example

Another important aspect of OOP is inheritance. Let's form an analogy with the teenager who is building a hotrod. That teenager doesn't normally start witha large chunk of steel and carve an engine out of it. Rather, the teenager will usually start with an existing engine and make improvements to it.

OOP lingo

In OOP lingo, that teenager extends the existing engine, derives from the existing engine, inherits from the existing engine, or subclasses the existing engine (depending on which author is describing the process) .

Just like in "souping up" an engine for a hotrod, a very common practice in OOP is to create new improved classes and objects by extending existing classdefinitions.

Extending the Game class

When you use Visual C# to create a new XNA game project, the IDE creates skeleton code for a new class. As you will learn later in this course, it isthen up to you to put some meat on the skeleton and turn it into a game. The first executable statement in the skeleton code is shown in Listing 1 .

Listing 1 . Extending the Game class.

public class Game1 : Microsoft.Xna.Framework.Game

The code in Listing 1 is the first executable statement in the definition of a new class named Game1 (or whatever name you give the new project) . The definition of the new class extends an existing class named Game , which resides in the Microsoft.Xna.Framework namespace. The existing class named Game , is the main controller for your new game. I will have much more to say about the Game class in a future module.

Reuse, don't reinvent

One of the major arguments in favor of OOP is that it provides a formal mechanism that encourages the reuse of existing programming elements. One of themottos of OOP is "reuse, don't reinvent."

Polymorphism example

A third important aspect of OOP is polymorphism. This is a Greek word meaning something like one name, many forms . This is a little more difficult to explain in non-programming terminology. However, we will stretch our imaginationa little and say that polymorphism is somewhat akin to the automatic transmission in your car. In my Honda, for example, the automatic transmissionhas four different methods or functions known collectively as Drive (in addition to the functions of Reverse, Park, and Neutral) .

Select Drive to go forward

As an operator of the automobile, I simply select Drive (meaning go forward) . Depending on various conditions at runtime, the automatic transmission systemdecides which version of the Drive function to use in every specific situation. The specific version of the function that is used is based on the currentconditions (speed, incline, etc.) . This is somewhat analogous to what we will refer to in a subsequent tutorial module as runtime polymorphism.

Object-oriented programming vocabulary

OOP involves a whole new vocabulary (or jargon) which is different from or supplemental to the vocabulary of procedural programming.

Questions & Answers

are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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Source:  OpenStax, Xna game studio. OpenStax CNX. Feb 28, 2014 Download for free at https://legacy.cnx.org/content/col11634/1.6
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