# 1.3 Scr0330: sequence, selection, and loop in scratch 2.0.  (Page 3/9)

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Also according to Wikipedia ,

"Pseudocode is an informal high-level description of the operating principle of a computer program or other algorithm. It uses the structural conventions of a programming language, but is intended for human reading rather than machine reading. Pseudocode typically omits details that are not essential for human understanding of the algorithm...
The purpose of using pseudocode is that it is easier for people to understand than conventional programming language code, and that it is anefficient and environment-independent description of the key principles of an algorithm."

## The sequence structure

We can describe the sequence structure using the pseudocode shown in Image 1 .

Thus, the general requirement for the sequence structure is that one or more actions may be performed in sequence after entry and before exit.

There may not be any branches or loops between the entry and the exit.

All actions must be taken in sequence.

## The action elements themselves may be structures

However, it is important to note that one or more of the action elements may themselves be sequence, selection, or loop structures.

If each of the structures that make up the sequence has only one entry point and one exit point, each such structure can be viewed as a single action elementin a sequence of actions.

The sequence structure is the simplest of the three, and there's not much more that I can say about it.

## The selection structure

The selection or decision structure can be described as shown in the pseudocode in Image 2 .

## Test a condition for true or false

Once again, there is only one entry point and one exit point.

The first thing that happens following entry is that some condition is tested for true or false .

The concept of something being true or false is commonly referred to as a boolean condition in computer programming (named after George Boole) .

If the condition is true, one or more actions are taken in sequence and control exits the structure.

If the condition is false, none , one or more different actions are taken in sequence and control exits the structure. (Note the inclusion of the word none here.)

## The action elements themselves may be structures

Once again, each of the action elements in the sequence may be another sequence, selection, or loop structure.

Eventually all of the actions for a chosen branch will be completed in sequence and control will exit the structure.

## Sometimes no action is required on false

It is often the case that no action is required when the test returns false. In that case, control simply exits the structure without performing any actions.

## The loop structure

The loop or iteration structure can be described as shown in the pseudocode in Image 3 .

As before, there is only one entry point and one exit point. Note that in this case, the exit point is not at the end of the pseudocode. Instead,it follows the test.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
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
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
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
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
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?
what is a peer
What is meant by 'nano scale'?
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 ?
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?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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