AS1: Software
Design
Unit 6: Software Design & Development
Cobzariu, Daniel 1/29/21 BTEC LEVEL 3 IN IT
,Contents
Introduction...........................................................................................................................................1
1 A. Programming Paradigm..................................................................................................................2
Characteristics of Procedural programming......................................................................................2
Characteristics of Object-oriented programming..............................................................................5
Characteristics of Event-driven programming...................................................................................8
1 B. Programming Languages...............................................................................................................10
Visual languages..............................................................................................................................10
Script languages...............................................................................................................................11
Mark-up languages..........................................................................................................................12
OTHER FACTORS THAT CAN INFLUENCE THE CHOICE OF A PROGRAMMING LANGUAGE...............12
1 C. Programming structures/constructs.............................................................................................14
Sequence.........................................................................................................................................15
Selection..........................................................................................................................................16
Iteration...........................................................................................................................................17
1 D. Data types.....................................................................................................................................18
1 E. PowerPoint: Software Design and Development Life Cycle..........................................................21
2. PowerPoint: Software Design and Development Quality of Code...................................................27
3. PowerPoint: Software Design and Development Readability of Code.............................................30
Introduction
In this assignment, I will describe the application and limits of different
types of programming paradigms along with the factors that influence the
developer when choosing a programming language. Other topics such as
sequence, selection and iteration will be covered too, including the
importance of having a variety of data types available to the programmer.
Next, I will outline the role of software design principles and software
structures in the IT systems development lifecycle. Additionally, the
importance of the quality of code and the factors that can improve the
readability of code will top up the assignment.
,1 A. Programming Paradigm
Programming paradigms are approaches used to classify programming
languages based on their characteristics. A programming paradigm
shouldn’t be confused with a programming language as they are two
different things. Consider paradigms as a way used to solve problems or
do tasks. There is a variety of programming paradigms and I will discuss
the characteristics of some of the most popular ones within the following
section.
Characteristics of Procedural programming
Procedural Programming (PP) might be the first programming paradigm a
new developer will discover and learn about. The procedural code is
directly instructing a device on how to accomplish a task in logical steps.
It is based on a liner top-down approach and considers data and
procedures as two separate entities. This programming paradigm has the
ability to split the code (functionalities) into smaller manageable parts
called functions or procedures. In procedural programming, the functions
are prioritized rather than data.
Procedural programming is most often used for relatively simple,
straightforward applications which do not involve many interacting sub-
systems. PP is particular to calculating engineering and scientific problems
as it is based on a fluid movement throughout the program as it runs.
There are different procedural programming languages including C,
Pascal, and PHP. An example of a program which can be created based on
this programming paradigm can be the software used by a washing
machine as the events occur sequentially. However, procedural
programming shouldn’t be used for developing complex systems as the
interaction between the functions can create too much complexity itself.
OOP was designed to resolve this problem.
One of the biggest advantages of procedural programming is that it can
break down a large program, meaning it will be divided into several
procedures and functions. This will ensure that code duplication is
mitigated, improving the maintainability and readability of the code.
Additionally, different functions can share data through global variables. I
will mention more advantages of this programming paradigm along with
some limitations later on.
, KEY FEATURES OF PROCEDURAL PROGRAMMING
1. Procedures are small programs also known as sub-programs and they
were created to help the developer avoid repetition. They can also include
local variables which are not available to the rest of the program. It is a
part of the program which executes a specific bit of an ordered set of
tasks that will perform an action.
2. Functions (routines) – they are similar to procedures by there’s a
main difference between them. They can be called within different parts of
the program. Functions are used to divide the code into smaller,
manageable parts in order to have more control over your program.
3. Predefined functions are built-in methods which are already defined
in the library/register of a programming language. For example, in java,
we have sName.toUpperCase() which is a pre-defined function which
automatically tells the program to put the text into uppercase letters. This
types of functions are helpful as they can save developer’s time.
4. Local variables are variables defined within a method or block of code
and they can only be used inside that method without interfering with the
outside code. A global variable, on the other hand, is the opposite of
that – they can be used anywhere within the program.
5. Parameter passing – a parameter refers to a type of variable which
can be passed into a function. In other words, it allows the developer to
pass variables in/out of a sub-program. The variables can be called by
value when you do not want the data to be changed, or call by reference
to modify the value of the parameter.
6. A programming library refers to a collection of precompiled routines
available within a program. In other words, it is a group of information
(code) such as functions or sub-routines. Libraries are helpful especially
Design
Unit 6: Software Design & Development
Cobzariu, Daniel 1/29/21 BTEC LEVEL 3 IN IT
,Contents
Introduction...........................................................................................................................................1
1 A. Programming Paradigm..................................................................................................................2
Characteristics of Procedural programming......................................................................................2
Characteristics of Object-oriented programming..............................................................................5
Characteristics of Event-driven programming...................................................................................8
1 B. Programming Languages...............................................................................................................10
Visual languages..............................................................................................................................10
Script languages...............................................................................................................................11
Mark-up languages..........................................................................................................................12
OTHER FACTORS THAT CAN INFLUENCE THE CHOICE OF A PROGRAMMING LANGUAGE...............12
1 C. Programming structures/constructs.............................................................................................14
Sequence.........................................................................................................................................15
Selection..........................................................................................................................................16
Iteration...........................................................................................................................................17
1 D. Data types.....................................................................................................................................18
1 E. PowerPoint: Software Design and Development Life Cycle..........................................................21
2. PowerPoint: Software Design and Development Quality of Code...................................................27
3. PowerPoint: Software Design and Development Readability of Code.............................................30
Introduction
In this assignment, I will describe the application and limits of different
types of programming paradigms along with the factors that influence the
developer when choosing a programming language. Other topics such as
sequence, selection and iteration will be covered too, including the
importance of having a variety of data types available to the programmer.
Next, I will outline the role of software design principles and software
structures in the IT systems development lifecycle. Additionally, the
importance of the quality of code and the factors that can improve the
readability of code will top up the assignment.
,1 A. Programming Paradigm
Programming paradigms are approaches used to classify programming
languages based on their characteristics. A programming paradigm
shouldn’t be confused with a programming language as they are two
different things. Consider paradigms as a way used to solve problems or
do tasks. There is a variety of programming paradigms and I will discuss
the characteristics of some of the most popular ones within the following
section.
Characteristics of Procedural programming
Procedural Programming (PP) might be the first programming paradigm a
new developer will discover and learn about. The procedural code is
directly instructing a device on how to accomplish a task in logical steps.
It is based on a liner top-down approach and considers data and
procedures as two separate entities. This programming paradigm has the
ability to split the code (functionalities) into smaller manageable parts
called functions or procedures. In procedural programming, the functions
are prioritized rather than data.
Procedural programming is most often used for relatively simple,
straightforward applications which do not involve many interacting sub-
systems. PP is particular to calculating engineering and scientific problems
as it is based on a fluid movement throughout the program as it runs.
There are different procedural programming languages including C,
Pascal, and PHP. An example of a program which can be created based on
this programming paradigm can be the software used by a washing
machine as the events occur sequentially. However, procedural
programming shouldn’t be used for developing complex systems as the
interaction between the functions can create too much complexity itself.
OOP was designed to resolve this problem.
One of the biggest advantages of procedural programming is that it can
break down a large program, meaning it will be divided into several
procedures and functions. This will ensure that code duplication is
mitigated, improving the maintainability and readability of the code.
Additionally, different functions can share data through global variables. I
will mention more advantages of this programming paradigm along with
some limitations later on.
, KEY FEATURES OF PROCEDURAL PROGRAMMING
1. Procedures are small programs also known as sub-programs and they
were created to help the developer avoid repetition. They can also include
local variables which are not available to the rest of the program. It is a
part of the program which executes a specific bit of an ordered set of
tasks that will perform an action.
2. Functions (routines) – they are similar to procedures by there’s a
main difference between them. They can be called within different parts of
the program. Functions are used to divide the code into smaller,
manageable parts in order to have more control over your program.
3. Predefined functions are built-in methods which are already defined
in the library/register of a programming language. For example, in java,
we have sName.toUpperCase() which is a pre-defined function which
automatically tells the program to put the text into uppercase letters. This
types of functions are helpful as they can save developer’s time.
4. Local variables are variables defined within a method or block of code
and they can only be used inside that method without interfering with the
outside code. A global variable, on the other hand, is the opposite of
that – they can be used anywhere within the program.
5. Parameter passing – a parameter refers to a type of variable which
can be passed into a function. In other words, it allows the developer to
pass variables in/out of a sub-program. The variables can be called by
value when you do not want the data to be changed, or call by reference
to modify the value of the parameter.
6. A programming library refers to a collection of precompiled routines
available within a program. In other words, it is a group of information
(code) such as functions or sub-routines. Libraries are helpful especially
