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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

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
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.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
analytical skills graphene is prepared to kill any type viruses .
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
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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