COMPUTER SCIENCES DEPARTMENT
COURSE:INFORMATION COMMUNICATION
TECHNOLOGY (ICT).
UNIT NAME: STRUCTURED PROGRAMMING.
NICHOLAS M Page 1 of 142
, TOPIC 1 : INTRODUCTION TO STRUCTURED PROGRAMMING.
Definitions
Structured programming – a technique for organizing and coding
computer programs in which a hierarchy of modules are used, each having
a single entry and a single exit point, and in which control is passed
downward through the structure without unconditional branches to higher
levels of the structure.
Computer hardware - refers to the physical parts of a computer and
related devices. Internal hardware devices include motherboards, hard
drives, and RAM. External hardware devices include monitors, keyboards,
mice, printers, and scanners.
The internal hardware parts of a computer are often referred to as
components, while external hardware devices are usually called
peripherals. Together, they all fall under the category of computer
hardware. Software, on the other hand, consists of the programs and
applications that run on computers. Because software runs on computer
hardware, software programs often have system requirements that list the
minimum hardware required for the software to run.
Software - refers to the set of electronic program instructions or data a
computer processor reads in order to perform a task or operation. In
contrast, the term 'hardware' refers to the physical components that you
can see and touch, such as the computer hard drive, mouse, and keyboard.
Software can be categorized according to what it is designed to accomplish.
There are two main types of software: systems software and application
software.
Systems Software
Systems software includes the programs that are dedicated to managing the
computer itself, such as the operating system, file management utilities, and
disk operating system (or DOS). The operating system manages the
computer hardware resources in addition to applications and data. Without
systems software installed in our computers we would have to type the
instructions for everything we wanted the computer to do.
Applications Software
Application software, or simply applications, are often called productivity
programs or end-user programs because they enable the user to complete
tasks, such as creating documents, spreadsheets, databases and
publications, doing online research, sending email, designing graphics,
running businesses, and even playing games! Application software is
specific to the task it is designed for and can be as simple as a calculator
NICHOLAS M Page 2 of 142
,application or as complex as a word processing application. When you begin
creating a document, the word processing software has already set the
margins, font style and size, and the line spacing for you. But you can
change these settings, and you have many more formatting options
available. For example, the word processor application makes it easy to add
color, headings, and pictures or delete, copy, move, and change the
document's appearance to suit your needs.
Program
This is a complete set of step-by-step instructions that control and direct the
computer hardware in carrying out a given task. Tasks may vary from very
simple e.g. computing surface area to complex ones like statistical analysis.
Programs are usually written to solve user problems on a computer.
Programming Language
This is a set of symbols and the rules that govern their rules that are
employed in the construction of a computer program.
Syntax
These are the rules of a language that govern the ways in which words,
symbols, expressions and statements may be formed and combined in that
language.
Semantics
These are the rules of language that govern meaning of statements in any
language.
Programmer
This is a person who is trained and/or specializes in the technique of
creating, maintaining and modifying computer programs.
Programming Languages
A programming language is a tool for developing executable models for a
class of problem domains.
Programming languages provide the basic building block for all software.
They are the means by which people can tell the computer how to carry out
a task.
Types of Structured Programming Language.
NICHOLAS M Page 3 of 142
, Pascal - A high-level programming language developed by Niklaus Wirth in
the late 1960s. The language is named after Blaise Pascal, a seventeenth-
century French mathematician who constructed one of the first mechanical
adding machines. Pascal is best known for its affinity to structured
programming techniques. The nature of the language forces programmers
to design programs methodically and carefully. For this reason, it is a
popular teaching language.
Despite its success in academia, Pascal has had only modest success in the
business world. Part of the resistance to Pascal by professional
programmers stems from its inflexibility and lack of tools for developing
large applications. To address some of these criticisms, Wirth designed a
new language called Modula-2. Modula-2 is similar to Pascal in many
respects, but it contains additional features.
C - C is a high-level and general-purpose programming language that is
ideal for developing firmware or portable applications. Originally intended
for writing system software, C was developed at Bell Labs by Dennis Ritchie
for the Unix Operating System (OS) in the early 1970s.
Ranked among the most widely used languages, C has a compiler for most
computer systems and has influenced many popular languages – notably C+
+
C is a structured, procedural programming language that has been widely
used both for operating systems and applications and that has had a wide
following in the academic community. Many versions of UNIX-based
operating systems are written in C. C has been standardized as part of the
Portable Operating System Interface (POSIX).
Fortran - Fortran is a programming language mainly used by the scientific
community. Its name is a contraction of FORmula TRANslation, and its aim
is to provide a way to tell computers to calculate complicated mathematical
expressions, with more ease than assembly language. FORTRAN is one of
the earliest programming languages. The original versions used punched
cards to write programs with. FORTRAN's age is both a strength and a
weakness. On one hand, FORTRAN has a huge number of libraries of code
available. However, Fortran also has many archaic features, especially in
the earlier versions.
FORTRAN was designed for scientists and engineers, and has dominated
this field. For the past 30 years FORTRAN has been used for such projects
as the design of bridges and aeroplane structures, it is used for factory
automation control, for storm drainage design, analysis of scientific data
and so on. Throughout the life of this language, groups of users have
written libraries of useful standard FORTRAN programs.
NICHOLAS M Page 4 of 142
COURSE:INFORMATION COMMUNICATION
TECHNOLOGY (ICT).
UNIT NAME: STRUCTURED PROGRAMMING.
NICHOLAS M Page 1 of 142
, TOPIC 1 : INTRODUCTION TO STRUCTURED PROGRAMMING.
Definitions
Structured programming – a technique for organizing and coding
computer programs in which a hierarchy of modules are used, each having
a single entry and a single exit point, and in which control is passed
downward through the structure without unconditional branches to higher
levels of the structure.
Computer hardware - refers to the physical parts of a computer and
related devices. Internal hardware devices include motherboards, hard
drives, and RAM. External hardware devices include monitors, keyboards,
mice, printers, and scanners.
The internal hardware parts of a computer are often referred to as
components, while external hardware devices are usually called
peripherals. Together, they all fall under the category of computer
hardware. Software, on the other hand, consists of the programs and
applications that run on computers. Because software runs on computer
hardware, software programs often have system requirements that list the
minimum hardware required for the software to run.
Software - refers to the set of electronic program instructions or data a
computer processor reads in order to perform a task or operation. In
contrast, the term 'hardware' refers to the physical components that you
can see and touch, such as the computer hard drive, mouse, and keyboard.
Software can be categorized according to what it is designed to accomplish.
There are two main types of software: systems software and application
software.
Systems Software
Systems software includes the programs that are dedicated to managing the
computer itself, such as the operating system, file management utilities, and
disk operating system (or DOS). The operating system manages the
computer hardware resources in addition to applications and data. Without
systems software installed in our computers we would have to type the
instructions for everything we wanted the computer to do.
Applications Software
Application software, or simply applications, are often called productivity
programs or end-user programs because they enable the user to complete
tasks, such as creating documents, spreadsheets, databases and
publications, doing online research, sending email, designing graphics,
running businesses, and even playing games! Application software is
specific to the task it is designed for and can be as simple as a calculator
NICHOLAS M Page 2 of 142
,application or as complex as a word processing application. When you begin
creating a document, the word processing software has already set the
margins, font style and size, and the line spacing for you. But you can
change these settings, and you have many more formatting options
available. For example, the word processor application makes it easy to add
color, headings, and pictures or delete, copy, move, and change the
document's appearance to suit your needs.
Program
This is a complete set of step-by-step instructions that control and direct the
computer hardware in carrying out a given task. Tasks may vary from very
simple e.g. computing surface area to complex ones like statistical analysis.
Programs are usually written to solve user problems on a computer.
Programming Language
This is a set of symbols and the rules that govern their rules that are
employed in the construction of a computer program.
Syntax
These are the rules of a language that govern the ways in which words,
symbols, expressions and statements may be formed and combined in that
language.
Semantics
These are the rules of language that govern meaning of statements in any
language.
Programmer
This is a person who is trained and/or specializes in the technique of
creating, maintaining and modifying computer programs.
Programming Languages
A programming language is a tool for developing executable models for a
class of problem domains.
Programming languages provide the basic building block for all software.
They are the means by which people can tell the computer how to carry out
a task.
Types of Structured Programming Language.
NICHOLAS M Page 3 of 142
, Pascal - A high-level programming language developed by Niklaus Wirth in
the late 1960s. The language is named after Blaise Pascal, a seventeenth-
century French mathematician who constructed one of the first mechanical
adding machines. Pascal is best known for its affinity to structured
programming techniques. The nature of the language forces programmers
to design programs methodically and carefully. For this reason, it is a
popular teaching language.
Despite its success in academia, Pascal has had only modest success in the
business world. Part of the resistance to Pascal by professional
programmers stems from its inflexibility and lack of tools for developing
large applications. To address some of these criticisms, Wirth designed a
new language called Modula-2. Modula-2 is similar to Pascal in many
respects, but it contains additional features.
C - C is a high-level and general-purpose programming language that is
ideal for developing firmware or portable applications. Originally intended
for writing system software, C was developed at Bell Labs by Dennis Ritchie
for the Unix Operating System (OS) in the early 1970s.
Ranked among the most widely used languages, C has a compiler for most
computer systems and has influenced many popular languages – notably C+
+
C is a structured, procedural programming language that has been widely
used both for operating systems and applications and that has had a wide
following in the academic community. Many versions of UNIX-based
operating systems are written in C. C has been standardized as part of the
Portable Operating System Interface (POSIX).
Fortran - Fortran is a programming language mainly used by the scientific
community. Its name is a contraction of FORmula TRANslation, and its aim
is to provide a way to tell computers to calculate complicated mathematical
expressions, with more ease than assembly language. FORTRAN is one of
the earliest programming languages. The original versions used punched
cards to write programs with. FORTRAN's age is both a strength and a
weakness. On one hand, FORTRAN has a huge number of libraries of code
available. However, Fortran also has many archaic features, especially in
the earlier versions.
FORTRAN was designed for scientists and engineers, and has dominated
this field. For the past 30 years FORTRAN has been used for such projects
as the design of bridges and aeroplane structures, it is used for factory
automation control, for storm drainage design, analysis of scientific data
and so on. Throughout the life of this language, groups of users have
written libraries of useful standard FORTRAN programs.
NICHOLAS M Page 4 of 142
