3. 2
Introduction
In this assignment I shall take on the persona of a programmer in a software house
specializing in varied and diverse projects, I will produce guidance that emphasizes that
paradigms and languages should be selected to suit the individual project rather than
the programmers favorite or most familiar language.
In this assignment I shall talk about the different programming paradigms and the key
advantages and features. I shall be talking about why readable code is good and the
uses for different languages along with a few data types and their uses.
4. 3
Task 1 – Programming Paradigms
Procedural programming is programming which follows a linear fashion. The code is
executed from top to bottom, unlike other languages where functions can be run in any
order.
Scripting languages such as Shell, Bash or Dash benefit greatly from the procedural
programming paradigm. Because scripting languages often don't need functions and
are in themselves a form of function, they can benefit from the linear readability and
execution.
The idea of the code being linear allows bugs and problems to be spotted more easily
as you don't have to jump down a rabbit hole of functions and loops to find a problem.
Procedural programming is appropriate for mathematic based programs, where each
mathematical step is carried out in a linear fashion to produce the result the
mathematician wants.
Procedural programming is inappropriate for game creation and development. Since
many games have multiple objects such as the player sprite, the players weapon, and
the player’s attributes; Procedural Programming cannot compute the abstract thought of
Object Orientated Design and thus is unsuited for game development or any programs
where objects are used.
Event driven programming is software that only runs when an event happens. An event
can be anything, from the temperature rising to a certain degree, to the system reporting
errors, and even an RSS feed updating.
Event Driven Programs live in an event loop. This is a constant, semi-infinite loop that
repeatedly sends a request to the appropriate system to see if the information has
changed. A program may also run on events passed to the program, a program which
involves the system passing events to the program is the Blue Screen of Death.
Windows will crash and pass the error to the Blue Screen of Death program which will
take then necessary precautions to fix the system and recover.
Event Driven Programming is highly suitable for critical systems such as Centrifuges. A
centrifuge is the control system that puts in orbit a piece of material around another
material. This is used to mix and cause controlled reactions with Uranium in Nuclear
Power plants.
Back in 2014, Stuxnet, the computer virus, attacked centrifuges directly. Because the
centrifuge started to heat up, the control system in place, created by Siemens, detected
this event and took the appropriate measures to cool down the system. Stuxnet directly
attacked the event handler which stopped the system from detecting any problem,
however, this is not a programming paradigm problem but more of a problem with not
encrypting the data.
5. 4
Event Driven Programming would not be appropriate for math programs, such as the
program which calculates Prime Numbers. Because this program uses the
mathematical formula N^2-1, this is not an event or a loop. It would only stunt and slow
down the calculations made by this program.
Object orientated programming is software based upon the principality of objects. An
object can be defined as anything, from a bike to the nuts holding the bike together.
Object Orientated Programming is essential in Computer Science as it's based around
Abstraction, and in the words of most computer science textbooks, "Computer Science
is the art of abstraction".
Abstraction means to take an object or function which is extremely complicated and to
allow it to run in parallel with other code which doesn't need to know how complicated
the abstraction is. An example of this is the transistors on a Central processing unit, we
don't have to know exactly how the electricity flows through the transistors for a
computer to work, but we can abstract this idea and call them Logic Gates instead.
Object Orientated programming is good for computational thinking, where problems are
solved using objects. It's a very natural way for computer science students to think, so
it's naturally the most favorable programming paradigm. As such, Object Orientated
Programming is also good for game design and development where each player has a
sprite, multiple attributes and possibly objects they can interact with in the world.
Object Orientated Programming is not suitable for mathematical based programming or
small scripts. Since most Object Orientated Programs force the paradigm on you (Java)
creating a small script to check to see if your internet connection is working may require
you making multiple objects and classes to check, this is not suitable as you can easily
perform the same task in 1 line of code in a scripting language.
Task 2 – Programming languages
5 factors that would influence the selection of a programming language used are:
The team’s knowledge – The team may already be proficient in a programming
language and may choose to use it due to experience. A team would rather use a
programming language they are already efficient in and know, then to learn another
programming language for a project unless that programming language was essential
for the project, such as using SQL to create a database as a database cannot be easily
made or operated on in conventional languages.
Platform – The platform you want to develop on will alter the language you use as
languages are normally platform specific with a few exceptions. Shell will not run on
Windows as it's a Unix specific scripting language, and likewise, Windows PowerShell
will not work on Unix-based operating systems such as Mac OSX or Linux.
6. 5
Specific uses of programming languages – Some programming languages are created
for a specific use and thus are used for that use. Examples of this is SQL which is made
only for databasing applications, you cannot use SQL for a web scraper and you cannot
use Hadoop for a databasing solution.
Need for speed – Some programming languages, due to being classed as level 3 or
higher programming languages are slow. Because of this, we may choose to use a
faster programming language such as Assembly or C to perform mathematical
calculations such as vector graphic calculation for games or calculating prime numbers.
Reliability – The language being chosen for the project must be a reliable programming
language with a lot of bugs and flaws fixed. NASA uses Pascal to program their rocket
ships and Mars rovers because the language has been tried and tested over time by
many users and is considered one of the most reliable programming languages today.
SQL – SQL is most appropriately used for, according to the ANSI standard, databasing
solutions as it can only be used to interact with a database. SQL cannot be used to
create fully blown systems with event handling and error correction facilities as it was
created to interact with relational databases.
HTML- HTML is most appropriately used to create the documents that appear on the
web that the user downloads when they want to visit a website. This is HTML’s only use
but it is used everywhere to create web-pages.
C, C++ - C and C++ are two different languages. C++ is a multi-paradigm programming
language which involves Procedural programming and Object orientated programming
and is mainly used for Game development and development of platform specific
programs such as Google Chrome. C is a procedural based programming language
used mainly for control systems or operating systems due to it’s fast operational
speeds.
Visual Basic – Visual basic is most appropriately used within Microsoft Office
applications such as Excel, as it’s the language Excel uses to create queries, variables
and other spreadsheet functions.
Sequence – A simple definition of a sequence is that it is a set of instructions to follow to
complete a
task. This is
often done in
a linear
fashion, one
after another.
Sequencing is
important in
algorithmic
structures as it
defines the right steps to take to complete an algorithm. An example of this in C can be
seen in the picture above, although the program converts 165 Fahrenheit into Celsius,
the actual algorithm “Celsius = (5/9) * (Fahrenheit-32)” uses sequencing to make sure
7. 6
the algorithm is correct. If we were to mess up the order the algorithm would not be the
same and thus the program will be void for it does not work.
Selection – Selection statements are used in programming to allow users to have an
option and the ability to make a choice within the program which is allows for non-linear
code. An example of this is the If, If else, and Else statements in C. This allows the user
to make a selection
about the code they
want to run, however
due to the abstract
nature of selection
statements the user
may not even know
the selection
statement is running.
An example of
selections statements
can be seen on the left
hand side. The user
will input an integer
and the program will
use comparison
statements to check
the integer the user
has inputted. If the
number is bigger than
10, use augmented assignments to add 1 to it. If the number is less than 10, add 10 to
it. If the number is neither, tell the user their input isn’t valid for this program.
Iteration – Iteration statements
are statements which allow code
to be repeated several times for
it to meet a certain criterion, a
certain amount of time or an
infinite amount. There are many
variations on the Iteration
statements, but on the left hand
side are two examples of
iteration statements. The first
statement is a for loop, this will
loop repeatedly until the
condition “y = 300” is true. We
create a variable called y and set
it to 0, and then every iteration we add n(10) to it.
The second loop is an infinite loop, it will iterate everything while true is true, but since
true is always true it’ll iterate infinitely.
8. 7
Task 3 - Data types
Type Range of Values Memory
Required
Purpose/Use
Byte 0-255 1 byte
Binary
Integer -32,768 to 32,767 or -2,147,483,648 to
2,147,483,647
4 bytes
Whole Number
under 2^32
Longint -9,223,372,036,854,775,808 to
9,223,372,036,854,775,807 4 bytes or 8
bytes
Whole number
under 2^64
Array
Infinite, limited by size of hard drive or architecture of
CPU.
16 bytes +
items in
array
Storing values in
organized list
Single
1.401298E-45 to
3.4028235E+38
4 bytes
Small numbers
Double -1.79769313486231570E+308 to -
4.94065645841246544E-324 and
4.94065645841246544E-324 to
1.79769313486231570E+308
8 bytes
Big numbers
Decimal
0 to +/-79,228,162,514,264,337
16 bytes
Decimal numbers
Boolean
True / False, 0/1, Yes/No
2 byes
True/False, 0/1,
Yes/No
String
0 to approximately 2 billion Unicode characters 10 bytes +
string length
Text
String(Fixed
Length)
1 to approximately 65,400 Length of
string Text
Unix Time
stamp
2^64 16 bytes Time since 1st
January, midnight
1970
Date
0:00:00 AM on January 1, 0001 to 11:59:59 PM on
December 31, 9999
8 bytes Day, Month, Year,
Time
9. 8
We have multiple data types for various reasons. One of these reasons is saving space.
When you define a variable with the data type Double, it will always use 8 bytes. When
you define a variable with data type Single, it will always use 4 bytes. This may not
seem like a lot but on microcontroller systems where memory is limited this is a lot. The
main reason we have data types is Abstraction. There are many different objects in the
world, so we need many different data types to define these objects. We could define a
Unix Timestamp as an integer, however, programmers may be confused by this as a
timestamp should be a timestamp object. We use abstraction and multiple datatypes to
help programmers understand the objects they are manipulating. In Python, all user
input, by default, is a string. If a programmer can’t see this clearly defined they may
think it is an integer.
Task 4 – Software design
Need
The system life cycle starts with an individual or organization needing an upgrade or
new software, and this creates the need for the new software. Without a need, there
isn’t a reason to create new software. In the words of many wise men “Don’t fix what
isn’t broken”.
Scope
The scope is the general outline of the idea that the developer has of what they are
planning to build. This includes detailing estimates on how long it might take for the
project to be completed, the expected amount of money that will be required to
complete the project, the amount of developers needed for this project, the software
which may be needed in order to aid creation of this system and perhaps the training
that the staff will have to undergo to use the new software.
Requirement analysis
The requirement analysis is where the programmers look at all the requirements of the
program and then determine how they are going to complete the project. This will
usually involve asking members of staff who have used the software for a long time their
opinions on the current software and how it could be improved upon.
Specification
This is the specific details of al the requirements that the program has to do and the
amount of time that the programmers will have to complete the program in. This is a
document that is agreed with both programmers and company.
10. 9
Design stage
The design stage is when the programmers prepare a design on how the program will
work, all of the programmers will have their own input on how each part of the program
should work. Once all the programmers have reached an agreement on how the
program will work they will put this into a document for future reference.
The design stage may also involve creating pseudocode for the project to help properly
visualize how it’s going to work.
Code development
The code development stage is when the programmers begin to create the code. Once
each programmer has created each of their individual parts and performed unit tests,
they will put all their code together normally using source control such as GitHub and
will compile the code.
Testing
The testing stage is when the programmers test the code as a whole program instead of
individual unit tests. This is one of the most important stages as it makes sure that it
can’t be broken by simple user input or other bugs which may annoy users to the extent
where they refuse to use the software.
Implementation
Implementation is the stage where you roll out the working and bug tested program
either to a small amount of chosen people, for example, one department or team to test
for any bugs or inconsistencies in the program, or to the whole organization if you are
confident in the code.
The implementation process also involves training all members of staff who need to use
the new software. Also, you could directly change over to the system which is
dangerous, may cause mass confusion amongst users and cause them to not want to
use the software. A better option is to parallel run the software next to the current
software and have the users slowly transition into using the new software by offering
greater functionality and ease of use.
Maintenance
Maintenance is the process in which the programmers constantly check for errors in the
program, and fix these errors and bugs as users report them. This is known as proactive
maintenance since the programmers don't stop looking for bugs until they are sure all
bugs are gone, after all bugs have dispersed the programmers may perform reactive
maintenance where maintenance is only performed when serious bugs occur. The
programmers will often create updates using the software life cycle described in this
document.
A top-down design chart is a way to plan a program by creating a chart and looking at it
from a top-down perspective, this is like pseudocode except you can visually see
selection statements in action.
11. 10
Pseudo-code meaning “False code” Is a type of design plan for a program written in
Plain English and doesn’t follow a specific language. This often uses words such as
“Load file” instead of “with open(file, “w”);”. These words are laid out in a similar way to
program code to help understand the flow of a program.
Flow charts show the process of what is happening in a program in a visual way. It
allows the programmer to design their program as a rough sketch, not pseudocode but
a more abstract way of thinking about code.
Task 5 – Quality & Readability of Cod
Quality of Code is how good looking, understandable, and maintainable code is. If code
is easily maintainable and follows a strict guide on how the code is to be written and
created, then it is considered good quality code.
Code should be easily readable as it allows for easier monkey patching, fixing bugs and
finding potential problems and security issues in the code. Many programmers, when
they come back to their own code find it confusing and hard to pick up again. If they
would have followed a “grammar” guide on code, it would be easier to pick up and
maintain again. The advantages of having a good grammar guide on code is that you
can understand other peoples code and they can understand yours more easily.
An example of a grammar guide is Python’s PEP8 which is universally used at Google
and Facebook.
In this definition, we have good variable names such as “user_input”. This follows 2
coding standards, snake case where you have a “_” between every word and no capital
letters. Capital letters are reserved for constant variables.
Here are ways you can make your code more readable.
Indentation – Indent your code so code that only runs after
selection statements is indented below the selection
statement, this makes it easier to read.
Indentation is important as it separates code which runs when
a selection statement is activated and code that’s run in a
procedural style.
Look at example 1, an example of well indented code. Each
selection statement is preceded with a tab character which
puts the next statement on the line below, this is nesting the
code.
12. 11
Example 2 is an example of how the code will look if
it’s not indented, you can’t read the code properly and
you’re not sure what statement is being run after the
selection statement runs.
Having a lot of white space around your code is
important as it makes code more readable. We use
whitespace in English as a rule to make our language
more readable, so it makes perfect sense to use it in
code to make it readable. In English, we can use
"Hello!How are you?I'm glad to see you!" as an
example. Here, the words "Hello!" and "How" look conjoined because there is no
whitespace, but once we add whitespace it should look cleaner and more readable;
"Hello! How are you? I'm glad to see you!".
In code the same rules apply, the code "3*6/4!==3||>50" looks extremely confusing and
unreadable. We can put whitespace before and after every operation which occurs,
which make the code read like this "3 * 6 / 4! == 3 || > 50". Notice also how we use a
factorial with a comparison operator, however in code with no-whitespace this can
become "!==" which means "Not equals to" but we wanted it to be "! ==" which means
"factorial comparison operator". White space is just as important for human readability
as it is for computer readability.
Variables should be aptly named using a naming convention such as snake case or
Pascal Case. By not having appropriately named variables you will become
discombobulated when you try to figure out what each variable stores and what it's for
when other people try to read your code or you read your code in a couple of months’
time. An example of this is using the variables "x, y, p, I, s". These variables are often
used as temporary storage in functions such as Bubble Sort. However, these variables
should never be used for actual variables because their names aren't clear and they are
relatively short variables which can get lost in the code. A good variable name for a
variable holding the sum of X + Y is "sum_x_y". In this, we implement snake casing and
naming the variable after what it stored inside it.
Useless comments are apparent in new coders’ code. Coders often feel like they have
to write pseudocode parallel to the code they have written
such can be seen in the example to the right. When the code
always says “return true” why explain it in a pseudo-code
format? It makes code messy and unreadable. You shouldn’t have to comment every
single line, just the things that may be confusing such as the algorithm for converting
Celsius to Fahrenheit, you could comment this with “Algorithm for converting Celsius to
Fahrenheit” to make it more readable.
13. 12
Conclusion
In this assignment I haven taken on the persona of a programmer in a software house specializing
in varied and diverse projects, I have produce guidance that emphasizes that paradigms and
languages should be selected to suit the individual project rather than the programmers favorite
or most familiar language.
In this assignment I have talk about the different programming paradigms and the key
advantages and features. I shall be talking about why readable code is good and the uses for
different languages along with a few data types and their uses.
I have come to the conclusion that programming languages should be selected based on the
suitability for the job and not on the programmers’ preference, however a programmer’s
preference should still have a say on what languages are used.
14. 13
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