<< Chapter < Page Chapter >> Page >
To have a clear understanding of computer science terms such as those that follow, we recommend lookingat Wikipedia
within a program, it is a region where a variable can be accessed and its valuemodified
global scope
defined outside the methods setup() and draw(), the variable is visible andusable anywhere in the program
local scope
defined within a code block or a function, the variable takes values that arelocal to the block or function, and any values taken by a global variable having the same name are ignored.

Array declaration and allocation

int[] arrayDiInteri = new int[10];
Got questions? Get instant answers now!

Programming structures

Conditional instructions

  • if: if (i == NMAX) { println("finished");} else {i++; }


  • while: int i = 0; //integer counter while (i < 10) { //write numbers between 0 and 9 println("i = "+ i); i++; }
  • for: for (int i = 0; i < 10; i++) { //write numbers between 0 and 9 println("i = "+ i); }

Initializing a table of random numbers

int MAX = 10; float[] tabella = new float[MAX]; for (int i = 0; i < MAX; i++) tabella[i] = random(1); //random numbers between 0 and 1 println(tabella.length + " elements:"); println(tabella);
Got questions? Get instant answers now!


Functions allow a modular approach to programming. In Processing, in the intermediate programming mode, we can define functions other than setup() and draw() , usable from within setup() and draw() .

Example of function

int raddoppia(int i) { return 2*i; }
Got questions? Get instant answers now!

A function is characterized by the entities (with reference to the example ) :

  • return type ( int )
  • name ( raddoppia )
  • parameters ( i )
  • body ( return 2*i )

Objects and classes

A class is defined by a set of data and functions. An object is an instance of a class. Vice versa, a class is the abstractdescription of a set of objects.

For an introduction to the concepts of object and class see Objects and Classes .

Example of class

Dot myDot; void setup() { size(300,20); colorMode(RGB,255,255,255,100); color tempcolor = color(255,0,0); myDot = new Dot(tempcolor,0); } void draw() { background(0); myDot.draw(10); } class Dot { color colore; int posizione; //****CONSTRUCTOR*****// Dot(color c_, int xp) { colore = c_; posizione = xp; } void draw (int ypos) { rectMode(CENTER); fill(colore); rect(posizione,ypos,20,10); } }
Got questions? Get instant answers now!

A class is characterized by the following entities (with reference to the example ) :

  • name ( Dot )
  • data ( colore, posizione )
  • constructor ( Dot() )
  • functions (or methods, draw() )

An object (instance of a class) is declared in the same way as we declare a variable, but we have to allocate a space for it(as we did for the arrays) by means of its constructor (with reference to the example ).

  • Declaration: ( Dot myDot; )
  • Allocation: ( myDot = new Dot(tempcolor,0) )
  • Use: ( myDot.draw(10); )

For a quick introduction to the Java syntax see Java Syntax Primer

With the following draw() method we want to paint the window background with a gray whose intensity depends on the horizontal position of themouse pointer. void draw() { background((mouseX/100)*255);} However, the code does not do what it is expected to do. Why?

The variable mouseX is of int type, and the division it is subject to is of the integer type. It is necessary to perform a type casting from int to float by means of the instruction (float)mouseX .

Got questions? Get instant answers now!

Questions & Answers

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
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 ?
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.
is Bucky paper clear?
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.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
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
what is system testing
what is the application of nanotechnology?
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
anybody can imagine what will be happen after 100 years from now in nano tech world
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
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Media processing in processing. OpenStax CNX. Nov 10, 2010 Download for free at http://cnx.org/content/col10268/1.14
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Media processing in processing' conversation and receive update notifications?