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Compare Image g with image c

If you compare the relational-logical expressions defined by the statements in the green areas of Image G with the expressions in the column headers in Image C , you should see a strong resemblance.

Parentheses are used to eliminate ambiguity and to clearly identify the operands of each operator in Image C . A 3D optical illusion is used for the same purpose in Image G . For example, it appears that everything to the right of the not operator in Image G is a little closer to the viewer than the green platform on which the word not is printed.

No detailed explanation of the construction is required

In the past several modules, I have walked you through the detailed drag, drop, insert, and typing steps required to produce scripts similar to thoseshown in Image G . Hopefully, you understand the mechanics of that process by now and it should no longer be necessary for me to walk you through the process.

Program behavior at runtime

The user begins by clicking the green flag in the upper right corner of the stage toinitialize all of the variables shown in Image D to 0. Then the user can change the value in each of the variables A , B , C , and D by moving the sliders shown in Image D .

Order of execution of scripts

Following that, when the user clicks the button at the bottom of Image D , each of the bottom three scripts in Image G is executed. Note that they are not all executed simultaneously due to practical limitations in the construction ofmost computers. However, I can't tell you the exact order in which they are executed because, as far as I know, that is not public information. It might belogical to assume that the individual scripts are executed from top to bottom, but such an assumption may not be correct.

Not important in this program

The order in which the three scripts are executed doesn't really matter in this program because the end result will be the same regardless of the order ofexecution. However, if two different scripts were to make modifications to the value of the same variable, the order in which those modifications are madecould matter a lot. I mention this simply as a word to the wise. Be careful and make certain that you don't write different event handlers that respond to thesame event and modify the same data in different ways even if that seems to appeal to your organizational sensibilities. In that case, you should combinethe different event handlers into a single event handler because the order of execution of the code within a script is well defined.

Evaluate the relational-logical expressions and take appropriate action

For each of the bottom three scripts in Image G , if the relational-logical expression given by the green blocks with the embedded orange blocks evaluatesto true, a value of true is set into and displayed by the variable identified bythe statement immediately below the word if . Otherwise, a value of false is set into and displayed by that variable as shown in Image D through Image F .

An online version of this program is available

A copy of this program has been posted online for your review (see Resources for the URL) . If you don't find the program using that URL, search the Scratch site for the usernamed dbal.

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
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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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