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Preview of the Scratch program

Now it's time to write and discuss a Scratch program. You should be able to replicate this program.

Hopefully by now you have worked your way through the Step-by-Step Intro and the various tips that you can access by clicking the question mark on the right side of your browser window when the window is open on theScratch website's programming interface . (Click the Create link on the Scratch website to open the programming interface . )

Hopefully you have also worked through several of the tutorials that you can find on Scratch as recommendedin the previous module. If not, you should do that before continuing with this module. In other words,by now you should have experience moving Scratch blocks around to cause your sprites to behave as you want them to behave.

In case you skipped the section titled An overview of computer programming , you might still want to go back and review the section on Variables .

The Scratch program named Variable01 .sb

Click here to run this program in your browser.

This Scratch program illustrates the creation and manipulation of two simple numeric variables.

Scratch variables can contain numeric values or strings of characters but this program will deal only with numeric values.

This program also illustrates the case sensitivity of variable names along with the ability to detect and respond to events fired by the keyboard andevents fired by the mouse.

A variable named Counter (upper-case C)

A variable named Counter (with an upper-case "C") is created, initialized to 0, and displayed in the upper-left corner of theStage area in the Scratch programming interface (see Image 1 ) . Although the label on this variable is small and difficult to read, you will see when you run this program that this is the topmost variable displayed on the Stage.

When the user clicks the green flag in the upper-right corner of the stage , the value of the variable is set to zero. Each time the userpresses the space bar, the value of the variable is increased by 1. Each time the user clicks the mouse in the blank area of the Stage, the value of thevariable is decreased by 1.

A variable named counter (lower-case c)

Another variable named counter (with a lower-case "c") is created, initialized to 0, and displayed below the Counter variable on the Stage. Again, when the user clicks the green flag in the upper-right cornerof the stage in Image 1 , the value of the variable is set to zero. Each time the user presses the space bar, the value of thisvariable is increased by 5. Each time the user clicks the mouse in the blank area of the Stage, the value of this variable is decreased by 5.

Discussion and sample code

Image 1 shows a cropped image of the Scratch programming interface for the program named Variable01 for Scratch v2.0.This image was produced by running the program online and clicking the blue button in the upper-right corner labeled See inside .

Image 1. cropped image of the scratch programming interface for the program named variable01.

Missing image.
Image 1. Cropped image of the Scratch programming interface for the program named Variable01.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
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.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
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
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
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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