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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

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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?
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit 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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