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The program code

Image 2 shows a full-size view of the center panel in Image 1 . This panel contains the program code associated with the button.

Image 2. the center programming panel for relational01.

Missing image.
Image 2. The center programming panel for Relational01.

Initialize the variables

The top script in Image 2 initializes the values of all the variables to zero when the user clicks thegreen flag. You have seen code like this several times before in this series of modules, so I won't discuss it further.

When the button is clicked ...

Each of the bottom three scripts in Image 2 are executed when the user clicks the button in the Stage area in Image 1 . These three scripts are very similar. However, they use three different relational operators to compare the values of the left and right operands and they set the values inthree different output variables accordingly.

I will walk you through the construction of one of the scripts with a detailed explanation of each step in the process. You should be able toextend that explanation to the other two scripts.

An if-else block

I'm going to walk you through the process of creating one of the bottom three scripts shown in Image 2 .

Image 3 shows the result of

  • Selecting the button sprite in the lower-right panel of Image 1 .
  • Selecting Control in the upper-left panel.
  • Dragging the block labeled when button clicked into the center panel.
  • Dragging an if-else block from the lower-left panel into the center panel.
  • Connecting the if-else block to the block that is labeled when button clicked .
By the way, in case I forgot to tell you before, you can set the name of the sprite to button by clicking in the dark gray area in the upper-right of Image 3 and typing the name of the sprite.

Image 3. starting to use an if-else block.

Missing image.
Image 3. Starting to use an if-else block.

Need to put a conditional clause in the pocket

Note the depressed pocket immediately to the right of the word if on the if-else block. We must drop another block of the correct shape into this pocket. The code in that block must evaluate to either true orfalse.

If that code evaluates to true, the code that we will insert into the mouth of the block immediately below the word if will be executed.

If the code that we drop into the pocket evaluates to false, the code that we insert into the mouth of the block immediately below the word else will be executed.

Where are the blocks with the correct shape?

There are two buttons (possibly more) that we can click in the upper left in Image 3 that will expose blocks with shapes matching the pocket immediately to the right of the word if in Image 3 :

  • Sensing
  • Operators

We used a block having the correct shape from the Sensing group in the earlier module titled Scr0130: Sequence, Selection, and Loop . An image of the blocks exposed by the Sensing button is shown in Image 12 in that earlier module.

Will use blocks from the Operators group

In this module, we will use three of the blocks that are exposed by clicking the green Operators button as shown in Image 4 .

Image 4. green blocks exposed by clicking the operators button.

Missing image.
Image 4. Green blocks exposed by clicking the Operators button.

Questions & Answers

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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
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
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
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?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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
Got questions? Join the online conversation and get instant answers!
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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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