<< Chapter < Page Chapter >> Page >

Image i. final screen output from the program named repeatuntil01.

Missing image.
Image I. Final screen output from the program named RepeatUntil01.

Doesn't have to be the last block in the script

Unlike the forever block, it is possible to connect another block to the bottom of a repeat until block. Therefore, it is not necessary for a repeat until block to be the last block in a script. This means that a program can continue to execute a repeat until block until a specified condition becomes true, and then move on to execute additional code.

This structure is more similar to the structures typically found in modern programming languages than are the structures required by the forever block. However, most modern programming structures repeat something while a condition is true instead of repeating it until a condition becomes true.

Available online

At the real risk of becoming really boring, I will tell you again that you can copy the code from Image H and run your own copy of the program. Also, the program has been posted online so that you can run it from there. (See the link to the online version in Resources .)

The loop blocks

The three blocks shown in Image J are the only blocks available to create loop structures in Scratch version 2.0.

(The forever if block that was available in v1.4 is no longer available in v2.0. However, its functionality can approximated by embedding an if block in a forever block.)

Image j. blocks that can be used to create loop structures in v2.0.

Missing image.
Image J. Blocks that can be used to create loop structures in v2.0.

In this and the previous program, I have provided discussions and sample programs using the three blocks in Image J as well as a discussion and sample program for a forever block with an embedded if block.

Run the programs

I encourage you to use the information provided above to write and run these three programs. Experiment with the code, making changes, and observing theresults of your changes. Make certain that you can explain why your changes behave as they do.

Just for fun, see if you can cause the cat to change color as it marches around in the circle.

I also encourage you to write the program described below.

Student programming project

Write a program named ForeverLoop03 that is very similar to the program named ForeverLoop01 . Once again, the cat marches in a circle when the user holds down the space bar (after first clicking the green flag) . However, this program also produces an audio output that is a nice drumbeat andthe cat marches in synchronism with the drumbeat.

My version of this program has been posted online so that you can run it from there. (See Resources for the link to the online version.)

Because of the speed of my computer and the speed of my Internet connection, the synchronization of the drumbeat and the animation in v2.0 is notas good as it was when running the program locally under v1.4. Losing the ability to run Scratch programs locally is one disadvantage of the changes thatwere made in v2.0.

Summary

In this module, I presented and explained three Scratch programs. One program uses a forever block in conjunction with an embedded if block to cause a sprite to move in a small circle whilethe space bar is pressed. I explained that it is not possible to connect another block to the bottom of a forever block. Therefore, if you use a forever block, it must be the last block in the script in which it is contained.

Questions & Answers

are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
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
has a lot of application modern world
Kamaluddeen
yes
narayan
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
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!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




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