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The program named ForLoop02

This program is an upgrade of the program named ForLoop01 . The behavior of this program is the same as the earlier program with the followingexceptions:

  • A slider variable named numberLoops is placed in the upper left corner of the Stage as shown in Image H .
  • When the user clicks the green flag, orthogonal axes are drawn through the origin of the Stage and the cat is placed at the origin.
  • When the user clicks the cat, the number of times the code in the repeat block is executed is determined by the current value of the slider variable.
  • As the code in the repeat block is repetitively executed, the path of the cat is traced out on the Stage as a series of short straightline segments, producing the circular path shown in Image I .

Image h. program forloop02 output after clicking the green flag.

Missing image.
Image H. Program ForLoop02 output after clicking the green flag.

Image i. program forloop02 output after clicking the cat.

Missing image.
Image I. Program ForLoop02 output after clicking the cat.

The program code

The code for this program is shown in Image J .

Image j. program code for the program named forloop02.

Missing image.
Image J. Program code for the program named ForLoop02.

Create a variable

The code in the left panel in Image J creates a variable with a slider named numberLoops and causes it to be displayed on the Stage as shown in Image I .

The initialization code

Although there is quite a lot of code that is executed when the green flag is clicked, there is nothing new there. All of that code has been explained in thisor earlier modules. For review, the green pen blocks and the blue go to blocks are used together to draw the Cartesian coordinates. Note that the pen is down when the initialization code finishes executing. As a result, a line willbe drawn whenever the cat sprite moves.

The repeat block

The only thing that is really new to this program is the use of the variable block named numberLoops to specify the number of times that the code in the repeat block will be executed each time the cat is clicked. Otherwise the code in the repeat block in Image J is the same as the code in the repeat block shown in Image F .

The operational difference

The operational difference is that each time the repeat block in Image F is executed, the code inside the repeat block will be executed 24 times. Each time the repeat block in Image J is executed, the number of times that the code inside the repeat block will be executed is specified by thecurrent position of the slider in Image I . This, in effect converts the static program named ForLoop01 into an interactive program in which the user has some control over the program behavior at runtime.

As mentioned earlier, because the pen is down, a line is drawn each time the cat sprite moves. That is what draws the circular path shown in Image I .

Online versions of these programs are available

Copies of these two programs have been posted online for your review (see Resources for the URL) . If you don't find the programs using that URL, search the Scratch site for the usernamed dbal.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
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
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
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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