<< Chapter < Page Chapter >> Page >

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 do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
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
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
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
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
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
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Teaching beginners to code. OpenStax CNX. May 27, 2013 Download for free at http://cnx.org/content/col11498/1.20
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Teaching beginners to code' conversation and receive update notifications?

Ask