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The same thing happens if we do override the draw method but leave the body empty. Therefore, the physical creation of the display window isbeing accomplished in the framework by code outside the draw method. The draw method simply controls the contents of the display window.

Code in the Cars class

Instance variables of type Car

The code in the Cars class (see Listing 2 ) begins by declaring two instance variables of the class named Car . By default, these two instance variables are initialized to null, meaning that they don'tcontain references to objects.

The inherited size method

The setup method begins by calling the method named size , which is inherited from the PApplet class. The documentation for the size method reads partially as follows:

"Defines the dimension of the display window in units of pixels. The size() function must be the first line in setup() . If size() is not used, the default size of the window is 100x100 pixels. The system variables width and height are set by the parameters passed to this function.

Do not use variables as the parameters to size() function, because it will cause problems when exporting your sketch. Whenvariables are used, the dimensions of your sketch cannot be determined during export. Instead, employ numeric values in the size() statement, and then use the built-in width and height variables inside your program when the dimensions of the display window are needed.

The size() function can only be used once inside a sketch, and cannot be used for resizing."

The display window

In case you were wondering about the type of object shown in Image 1 , here is some information from the PApplet documentation.

"This class extends Applet instead of JApplet because 1) historically, we supported Java 1.1, which does not include Swing (without an additional,sizable, download), and 2) Swing is a bloated piece of crap. A Processing applet is a heavyweight AWT component, and can be used the same as any other AWTcomponent, with or without Swing.

Similarly, Processing runs in a Frame and not a JFrame. However, there's nothing to prevent you from embedding a PApplet into a JFrame, it's just thatthe base version uses a regular AWT frame because there's simply no need for Swing in that context. If people want to use Swing, they can embed themselves asthey wish."

Stated differently, the display window that you see in Image 1 is a standard java.awt.Frame object.

Instantiate Car objects

After setting the size of the display window, the setup method in Listing 2 instantiates two objects of the Car class and saves the object's references in the instance variables named myCar1 and myCar2 .

We haven't discussed the constructor for the Car class yet, but we can see in Listing 2 that the constructor for one Car object is passed a color value of pure red and the constructor for the other Car object is passed a color value of pure blue.

Let's talk about color

If you are an experienced Java programmer, what I am about to tell you is going to seem really strange.

Primitive types

As an experienced Java programmer, you know that the Java language defines the following eight primitive types:

Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
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Source:  OpenStax, The processing programming environment. OpenStax CNX. Feb 26, 2013 Download for free at http://cnx.org/content/col11492/1.5
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