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A moonscape background from the gallery was used for the project shown in Image 4 .

Controlling the behavior of a sprite

You control the behavior of a sprite by writing one or more scripts that belong to the sprite. In reality, each script is an event handler ofsorts. Usually you will have one event handler that executes when the user clicks the green flag at the top right in Image 6 . This is particularly true if any special initialization code is required for the sprite, such assetting the current costume to a particular costume, for example.

In addition to the green-flag script, you can also write scripts to handle mouse events, key events, and a special type of event that fires when one spritebroadcasts a message to one or more other sprites. Therefore, Scratch projects are not only sprite-based; they are also event-based. These arerelatively advanced concepts in most programming environments. However, Scratch was designed in such a way as to make it easy to write event-handlerscripts to control the behavior of sprites.

Drag and drop programming

Creating Scratch programs involves very little typing. Instead, scripts are created by constructing stacks of blocks, where each block imparts somespecific behavior to a sprite or to the stage. For example, the project being developed in Image 6 has a stage, (which is always the case) but doesn't yet have any sprites. The stage is represented by the rectangularthumbnail image in the bottom right area of Image 6 . Any sprites that are added to the project would also appear as thumbnail images in that same area.I will refer to this area as the sprite list area.

The physical process for writing a script is as follows:

  1. Select the stage or a sprite in the sprite list area that is to be programmed.
  2. Select the Scripts tab in the center pane.
  3. Select one of the color-coded buttons in the toolbox button area at the top left to expose the blocks contained in a particular toolbox in thetoolbox pane. The toolbox pane is the large pane on the left.
  4. Drag blocks from the toolbox to the scripts (center) pane. (Several blocks have already been dragged to the scripts pane in Image 6 .)
  5. Go back to 3 and continue this process until you have all of the blocks that you need in the scripts pane.
  6. Snap the blocks together in the correct arrangement to create a script that produces the desired behavior.

You will learn the details of such operations in future modules.

Costumes and sounds

Selection of the other two tabs showing at the top of the center pane in Image 6 exposes the controls for importing, editing, and creating costumes and backgrounds, as well as recording and/or importing sound files to be used asmusic and sound effects.

The Scratch programming language

Despite the fact that Scratch has amassed a huge following since its Beta release on March 4, 2007, in my opinion, the language isn't a particularly goodlanguage from a computer science viewpoint. Of the ten or fifteen programming concepts that most computer science professors consider to befundamental to good programming, Scratch supports only a few. Those few include:

Questions & Answers

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
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
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
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Teaching beginners to code. OpenStax CNX. May 27, 2013 Download for free at http://cnx.org/content/col11498/1.20
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