AKTU MCA I FCET UNIT I notes
Syllabus
Unit I
Introduction to
Computer: Definition, Computer Hardware & Computer Software Components:
Hardware – Introduction, Input devices, Output devices, Central Processing
Unit, Memory- Primary and Secondary. Software - Introduction, Types – System
and Application.
Computer
Languages: Introduction, Concept of Compiler, Interpreter &Assembler
Problem
solving concept: Algorithms – Introduction, Definition, Characteristics,
Limitations,
Conditions in pseudo-code, Loops in pseudo code.
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UNIT
I
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COMPUTER: AN INTRODUCTION
Like many other machines, a computer
is also a system. Any system has three main components input-process-output. As
our human body, we listen from our ear process it under our brain and when we
find some result we can show the output with the help of mouth (speak) or hand
(writing). No system can work independently. Like many other systems, computers
are also a system, it takes command, instructions, raw data, etc. with the help
of specified input devices and then processes it with a special device that is
called a processor (processor work on preloaded program) and then produces a
result. It can be understood with an example suppose that you want to find the
result of 15 * 5 to do this you can take the help of a computer. The computer
takes input (15 * 5) then the processor processes it on the basis of a table
program that is preloaded and gets the result i.e. 75. But how could you know
the result so there are some output devices which are used to show the result
that is produced by the processor? In very short we can say that a computer is
a system for data processing. A computer has a huge storage capacity. We can
store millions of libraries on a single computer. A computer can store
any amount of information because of its secondary storage. Every piece of
information can be stored as long as desired by the user and can be recalled
when required. A byte is a storage unit. Normally 1 TB (TeraByte) hard disk is
used in desktop. Later we will discuss these units in detail.
Definition: we can define a computer in
different perspectives like a Computer is a machine, a computer is an
electronic device, a Computer is a data processor, and a computer is a digital
device. Etc. but in a much-summarized way…
A computer is a digital device that
takes data process it under some specific program and produces some meaningful
output.
Mainly computer is a digital data
problem solver or action performer. It takes data to process it on the basis of
some previously loaded program (set of instructions) and produces the desired
result. A computer can’t do anything that is not pre-loaded into it.
Characteristics of a computer
Speed The speed of
computers is very fast. It can perform in a few seconds the amount of work that
human beings can do in an hour. When we are talking about the speed of a
computer we do not talk in terms of seconds or even milliseconds it is nanoseconds.
The computer can perform about 3 to 4 million arithmetic operations per second.
The unit of speed of the computer is Hertz. A normal desktop computer processor
speed is between 3.50 to 4.2 GHz.
Accuracy accuracy of computer
is very high or in other word we can say that if program design is very good
Computer cannot do any mistake. Basically, the accuracy of the program is
depending on the accuracy of program writing. So after a long period of time on
program testing and the debugging program becomes more accurate. The accuracy
of a particular program becomes more accurate Day by day.
Alertness Computer
is a machine so it does not get tired and hence can work for long time without
creating any error or mistake. It means that there is no different to perform
one arithmetic operation 10 arithmetic operation or for thousand or millions of
arithmetic operations the result will be same because of there is no issue of
tiredness like human beings. The computer always works on full alert mode.
Versatility Modern era demands
versatility from everyone. In cricket, the all-rounder is more on the demand of
the player. The same player has also liked if the batsman is also a bowler; he
is also a good fielder. In the same way, people want to get more and more work
from the same machine. Nowadays we can perform any task with the help of a
computer. we can type, watch movies, listening songs, internet browse, download
files, perform many government-related official jobs using e-governance and so
many other useful tasks can be done using a single machine it is called
versatility. A computer is capable of performing almost any task provided that
the task can be reduced to a series of logical steps.
A computer is a digital device that takes data process it
under some specific program and produces some meaningful output.
Mainly computer is a digital data problem solver or action
performer. It takes data to process it on the basis of some previously loaded
program (set of instructions) and produces the desired result. A computer can’t
do anything that is not pre-loaded into it.
Artificial Intelligence (AI):
Above characteristics belong to some traditional computer systems nowadays
modern computers come with AI. It means that it can perform much better than
previously loaded programs. An artificial intelligence inbuilt computer can
take its own decision. Google search is based on artificial intelligence it
produces the result of searching on the basis of a particular user searching
experience. This type of computer can change the program it can modify the
loaded program
Elements of a Computer System set up:
There are mainly five elements of a
computer system.
(i)
Hardware: the physical part of the computer
system that we can see, touch, and move from one place to another is called
hardware. For example mouse, keyboard, optical scanner, monitor, printer,
processor, etc.
(ii)
Software: it is the part of
the computer system that we cannot see but the whole system is based on that
part, we call it software. Software is mainly a collection of programs. And the
program is a set of instructions to solve any given problem or to perform any
particular job. All the work of the computer depends on the program. The
computer cannot do anything that is not already written in the program, that
is, what the computer can do. Everything is already written in the program.
Basically, there are two major classifications of software, namely System Software
and Application Software.
System software: software that is for a computer system. A computer
system consists of many parts so a different type of software is needed for
each part. In other, we can say that system software is for hardware. A user can
not directly interact with system software but without it, he cannot access the
services of particular software. If said in very simple words, then it can be
said that the system software acts as an intermediary between the hardware of
the computer and the user who uses that computer.
For example, if we want to use a
printer, then without printer software (sometimes it is called printer driver
software), we cannot use it. With the help of printer software, the computer
performs various functions of the printer. Sometimes it is also called device
drivers. ROM -BIOS driver, printer driver, USB drivers, motherboard
drivers, VGA drivers are some examples of system software. Sometimes the
operating system is also considered as system software.
Application software: Application software is the software that is made for a
particular work. It is written for a particular application. It is also called
end-user software. End-user means that the user interacts with. A computer user
directly interacts with it .every application software is written for a
particular work for example word processor software is made for only word
processing, paintbrush software is made only for painting type of work, the
internet browser is used for browsing the internet, etc.
Ms-office, ms-paint, Tux-paint,
notepad, adobe reader, Mozilla Firefox, Google Chrome, calculator are some very
common examples of application software.
(iii)Human being the most
important element of a computer system is its users.
The user's convenience is seen while
designing the interface of any application software. We cannot imagine the
computer world without human beings. The computer is made by humans and it is
made for humans only. Humans cannot be separated from a computer element. Data
analysis, computer programmer, server administrator, and computer operators are
some important examples of this.
(iv)
Data:
data is also a very important element of a computer system. Basically, a
computer is a data processor so without data, a computer cannot perform
anything. Any raw fact is called data and after processing this data becomes
information. Suppose we have to find 799 whether it is an odd or even number,
then we will call 799 as data, and the rule with which we will find out whether
it is even or odd is called a program. And the result that will come out will
be output. So both the result and the program depend on our data, so data is
mandatory for computers. The same data can present many types of results; hence
the demand for data analysis has also increased nowadays. Text, audio, images,
and video are some most common forms of data. With the help of appropriate
software word processing, image processing, audio processing, and video
processing can be performed to get desired output.
(v)
Network setup it is not possible to imagine computers without the
internet nowadays. Internet is a network of networks. it means that the
internet is dependent on various kinds of networks. Most of the networks are
belong to the Telecom network for example BSNL, Airtel, jio, etc. So it is very
important for the Internet to have this kind of network.
Components of a Computer System
There
are basically three main components of a computer system. Input unit, Process
unit, and Output unit. Our computer system is based on these three main
components. If we talk about any element of the computer, then it will be
related to any one of these three components. To understand the working of the
computer, it is very important to understand how these three components are related,
and to understand this; we can take the help of a block diagram.
Input
unit: The
main function of this unit is to take data, commands or instructions. To
receive data from the user or any other means input devices are used. Mouse,
keyboard, joystick, scanner, are some most popular examples of input devices.
Process
unit of C.P.U.(central processing unit ): This is the core unit of a computer system. It is also
called the brain of the computer. Basically, the main task of the computer is
done by this unit. Because of this unit computer is called a data processor. In
a very simple word, we can say that it is not a part of a computer but it is a
computer. The job of this unit is very complicated so it consists of three
parts CPU, memory, and storage.
CPU
(central processing unit): it is a combination of ALU (arithmetic and Logical unit) and
CU (control unit).ALU performs arithmetic and logical operation such as
addition; subtraction comparison etc. and CU perform control operation of the
computer system.
Memory:
it is a helper of the CPU. As
you know we cannot do anything without memory in the same way CPU also needed
memory to store temporary data in the meanwhile of processing. It is used from
taking data from input devices to show the result. Everywhere temporary memory
is required. To do this RAM (Random Access Memory) is used along with the CPU.
There is also a special type of memory is used that is call ROM (Read Only
Memory).it holds data permanently. It is very costly so only the data that is
required for opening the computer is stored in it. So it can be said that there
are two types of computer memory RAM and ROM. always remember only RAM is
called computer main memory.
There are two main types of computer
memory: primary memory and secondary memory.
Primary memory is also known as main
memory or internal memory. It is the memory that the CPU can access directly.
Primary memory is volatile, meaning that data is lost when the power is turned
off. The two main types of primary memory are:
- Random access memory (RAM) is used to store data
that the CPU is currently using. RAM is very fast, but it is
also expensive.
- Read-only memory (ROM) is used to store data that
the computer needs to boot up and operate. ROM is
non-volatile, meaning that data is retained even when the power is
turned off.
Secondary memory is also known as
external memory or auxiliary memory. It is used to store data that the CPU does
not need to access immediately. Secondary memory is non-volatile and is
typically much slower than primary memory. Some common types of secondary
memory include:
- Hard disk drives (HDDs) are the most common type
of secondary memory. They are relatively slow, but they can
store large amounts of data.
- Solid-state drives (SSDs) are a newer type of
secondary memory that is much faster than HDDs. SSDs use flash memory
to store data, which is the same type of memory used in USB drives and
SD cards.
- Optical storage devices such as
CDs, DVDs, and Blu-rays are used to store data that needs to be
portable or archived.
In addition to primary and secondary
memory, there are a few other types of memory that are used in computers:
- Cache memory is a small amount of very fast memory
that is used to store data that the CPU is likely to need soon. Cache
memory is typically located between the CPU and primary memory.
- Register memory is a small amount of memory that
is built into the CPU. Register memory is used to store data that the
CPU is currently working on.
The different types of computer
memory are designed for different purposes. Primary memory is used to store
data that the CPU needs to access immediately, while secondary memory is used
to store data that the CPU does not need to access immediately. Cache memory is
used to speed up access to data that the CPU is likely to need soon, while
register memory is used to store data that the CPU is currently working on.
Difference between RAM and ROM
Difference |
RAM |
ROM |
Data
retention |
RAM
is a volatile memory that could store the data as long as the power is
supplied. |
ROM
is a non-volatile memory that could retain the data even when power is turned
off. |
Working
type |
Data
stored in RAM can be retrieved and altered. |
Data
stored in ROM can only be read. |
Use |
Used
to store the data that has to be currently processed by CPU temporarily. |
It
stores the instructions required during bootstrap ( start )of the computer. |
Speed |
It
is a high-speed memory. |
It
is much slower than the RAM. |
CPU
Interaction |
The
CPU can access the data stored on it. |
The
CPU can not access the data stored on it unless the data is stored in RAM. |
Size
and Capacity |
Large
size with higher capacity. |
Small
size with less capacity. |
Used
as/in |
CPU
Cache, Primary memory. |
Firmware,
Micro-controllers |
Accessibility |
The
data stored is easily accessible |
The
data stored is not as easily accessible as in RAM |
Cost |
Costlier |
cheaper
than RAM. |
Storage
devices:
Storage devices have evolved significantly
over the years, from the early days of punched cards and magnetic tapes to the
modern-day SSDs and cloud storage.
Punched cards: Punched cards were one of the
earliest forms of data storage. They were used to store data for computers and
other machines. Punched cards were made of cardboard and had holes punched in
them to represent data.
Punched
cards
Magnetic tapes: Magnetic tapes were another
early form of data storage. They were used to store data for computers and
other machines. Magnetic tapes were made of plastic or metal and had a magnetic
coating. Data was stored on the magnetic tape by magnetizing and demagnetizing
the coating.
Magnetic
tapes
Hard disk drives (HDDs): HDDs are the most
common type of secondary storage device today. They use a spinning platter
coated in magnetic material to store data. Data is read and written to the
platter by a read/write head.
Solid-state drives (SSDs): SSDs are a newer
type of secondary storage device that is much faster than HDDs. SSDs use flash
memory to store data, which is the same type of memory used in USB drives and
SD cards.
Cloud storage: Cloud storage is a type of
storage device that is hosted over the internet. It is convenient and
accessible from anywhere, but it can be more expensive than traditional storage
devices.
Evolution of storage devices
The evolution of storage devices has been
driven by a number of factors, including:
·
The need for more
storage capacity: As computers have become more powerful, the need
for more storage capacity has increased.
·
The need for faster
storage: As computers have become faster, the need for faster storage
has increased.
·
The need for more
portable storage: As people have become more mobile, the need for
more portable storage has increased.
·
The need for more
affordable storage: As the cost of computing has decreased, the cost
of storage has also decreased.
Future of storage devices
The future of storage devices is likely to be
shaped by a number of trends, including:
·
The continued growth
of data: The amount of data being generated and stored is growing
exponentially. This is driving the need for more storage capacity.
·
The rise of artificial
intelligence (AI): AI is becoming increasingly important in a wide range
of applications. AI applications require large amounts of data to train
and operate. This is driving the need for faster and more efficient
storage devices.
·
The growth of the
cloud: Cloud storage is becoming increasingly popular. Cloud storage
providers are developing new technologies to improve the performance and
reliability of cloud storage.
CD/DVD
CDs
and DVDs are optical disc storage formats that were very popular in the past,
but have been largely replaced by digital storage formats such as SSDs and
cloud storage.
CDs
were first released in 1982 and could store up to 700 MB of data. DVDs were
first released in 1996 and could store up to 4.7 GB of data. DVDs were later
updated to support dual-layer discs, which could store up to 8.5 GB of data.
CDs
and DVDs were used to store a variety of data, including music, movies,
software, and video games. CDs were also used to distribute music and software
online.
CDs
and DVDs have a number of advantages over other storage formats. They are
relatively inexpensive, durable, and portable. However, CDs and DVDs are also
relatively slow and have limited storage capacity.
The
evolution of digital storage formats has led to the decline of CDs and DVDs.
Digital storage formats such as SSDs and cloud storage are faster, have more
storage capacity, and are more convenient to use.
Output
units generally user interact with the
input units and output units. After performing very complex data processing job
processor produce a result but it is in electronic form human being cannot
understand it. So to convert results into human-readable form output devices
are used. The main function of the output unit is to convert digital data into
a human-understandable form. Monitor and printer are the two most common output
devices. Monitor display the result in a soft form on-screen and the printer
produce the result on paper in a hard form so sometimes soft copy and hard copy
terms are used for monitor and printer respectively. Speaker is also an output
device that is used to produce audio for listening.
Types
of output devices
There are a wide variety of output devices
available, each with its own advantages and disadvantages. Some common types of
output devices include:
Monitors: Monitors are the most common type of output
device. They display text, images, and videos to the
user. Monitors are available in a variety of sizes and
resolutions, and can be used for a variety of tasks, such as working
on documents, watching movies, and playing games.
Printers: Printers print text and images onto paper. Printers
are available in a variety of types, including laser printers, inkjet
printers, and thermal printers. Laser printers are the fastest type
of printer, but they are also the most expensive. Inkjet printers are
less expensive than laser printers, but they are also slower and can be
more expensive to operate in the long run. Thermal printers are the least
expensive type of printer, but they are also the slowest and produce the
lowest quality prints.
Speakers: Speakers reproduce sound from a computer. Speakers
are available in a variety of sizes and configurations, and can be used
for a variety of tasks, such as listening to music, watching
movies, and playing games.
Plotters: Plotters create high-quality drawings and
schematics. Plotters are typically used in engineering and design
applications.
Other types of output devices
In addition to these common types of output
devices, there are a number of other specialized output devices available, such
as:
Digital signage: Digital signage displays are used to
display digital content, such as text, images, and
videos, in public places.
Projectors: Projectors project images and videos onto a
screen. Projectors are typically used in conference rooms and classrooms.
Interactive whiteboards: Interactive whiteboards allow users to
interact with a computer using a stylus or their finger. Interactive
whiteboards are typically used in classrooms and businesses.
Virtual reality (VR) headsets: VR headsets allow users to experience a
simulated environment.
Augmented reality (AR) headsets: AR headsets overlay digital information
onto the real world.
Internet of Things (IoT) devices: IoT devices collect and transmit data to
the cloud.
Artificial intelligence (AI) devices: AI devices process data and make decisions
using machine learning algorithms.
Computer
Generations
We can divide the generation of
computers into five stages. The sequence of computer generation is as follows.
First
Generation (1940-1956)
Vacuum tubes or thermionic valve
machines are used in first-generation computers.
Punched card and the paper tape were
used as an input device.
For output printouts were used.
ENIAC (Electronic Numerical
Integrator and Computer) was the first electronic computer is introduced in
this generation.
Second
Generation (1956-1963)
Transistor technologies were
used in this generation in place of the vacuum tubes.
Second-generation computers have
become much smaller than the first generation.
Computation speed of
second-generation computers was much faster than the first generation so
it takes lesser time to produce results.
Third
Generation (1963-1971)
Third generation of
computers is based on Integrated Circuit (IC) technology.
Third generation
computers became much smaller in size than the first and second generation, and
their computation power increased dramatically.
The third generation
computer needs less power and also generated less heat.
The maintenance cost
of the computers in the third generation was also low.
Commercialization of
computers was also started in this generation.
Fourth
Generation (1972-2010)
The
invention of microprocessor technology laid the foundation for the fourth
generation computer.
Fourth
generation computers not only became very small in size, but their ability to
calculate also increased greatly and at the same time they became portable,
that is, it became very easy to move them from one place to another.
The
computers of fourth-generation started generating a very low amount of heat.
It
is much faster and accuracy became more reliable because of microprocessor technology.
Their
prices have also come down considerably.
Commercialization
of computers has become very fast and it is very easily available for common
people.
Fifth Generation (2010- till date)
AI (Artificial intelligence) is the
backbone technology of this generation of computers. AI-enabled computers or
programs behave like an intelligent person that’s why this technology is called
artificial intelligence technology.
In addition to intelligence,
the speed of computers has also increased significantly and the size has also
reduced much earlier than even the computer on the palm has been used.
Some of the other popular advanced
technologies of the fifth generation include Quantum computation,
Nanotechnology, Parallel processing, Big Data, and IoT, etc.
Computer
language
A computer cannot understand our
language because it is a machine. So, it understands machine language or we can
say that the main language of computers is machine language. Now the question
arises that which language a machine understands? The answer is very easy; it
understands the language of on and off.
But due to the complexity of the
work of computers nowadays, it is not easy to work with the computer only in
the language of on and off, so some other languages are used for the computer.
Therefore, the language of computers
is mainly divided into three parts.
1.
Machine language: - Machine language is the
language in which only 0 and 1 two digits are used. Any digital device only
understands 0 and 1.It is the primary language of a computer that the computer
understands directly, the number system which has only two digits is called a
binary number system so we can say that the computer can understand only binary
codes. Binary codes have only two digits 0 and 1 since the computer only
understands the binary signal i.e. 0 and 1 and the computer's circuit i.e. the
circuit recognizes these binary codes and converts it into electrical signals.
In this, 0 means Low /off and 1 means High/ On.
2.
Assembly Language: - We use symbols in assembly
language because machine language is difficult for humans, so assembly language
was used to make communication with the computer easier. That is why it is also
called symbol language. Sometimes it is also called low-level language. But one
thing must be understood that the computer understands only and only the
language of the machine. So the computer needs a special type of program,
called assembler, to understand the assembly language. The assembler converts
programs written in assembly language into machine language so that the program
written by us can be understood by the computer. Assembly language is the
second generation of programming language.
3.
High-Level Language: - Symbols were used in
assembly language, so it was difficult to write a program with only symbols, so
the need was felt for a language that uses the alphabet of ordinary English or
we can say it that we can understand and write easily. Writing and
understanding high-level language is much easier than assembly language, so it
is quite popular in the computer world with the help of which it became very
easy to write many programs. As the assembler was used to convert assembly
language to machine language, a special type of software called compiler is
used to convert high-level language to machine language. Some of the major
high-level programming languages are C, C ++, JAVA, HTML, PASCAL, Ruby, etc.
Compiler, Interpreter, Assembler.
A compiler, interpreter, and
assembler are three different types of software programs used in the process of
programming and software development.
Compiler:
A compiler is a software program
that converts the source code written in a high-level programming language into
machine code, which can be executed directly by a computer's CPU. It is used to
create standalone executable files that can be run on a specific platform. The
compiler takes the entire source code as input, performs a series of checks and
optimizations, and then generates the executable code.
Interpreter:
An interpreter is a software program
that executes the source code line by line. Instead of generating machine code,
it translates the source code into an intermediate code, which is then executed
by the interpreter. This type of program is often used in scripting languages,
where code is interpreted at runtime. An interpreter is slower than a compiler
because it needs to read and interpret each line of code each time the program
is run.
Assembler:
An assembler is a software program
that converts assembly language into machine code. Assembly language is a
low-level programming language that uses mnemonic codes to represent
instructions that can be executed directly by a computer's CPU. Assemblers are
used to create executable files and libraries that can be linked with other
code. Unlike compilers and interpreters, assemblers work directly with machine
code, making them very efficient but also very difficult to use.
In summary, compilers, interpreters,
and assemblers are all used to translate human-readable code into
machine-executable code, but they do it in different ways and for different
purposes.
ALGORITHM
An algorithm is a finite sequence of
well-defined instructions, typically used to solve a class of specific problems
or to perform a computation.
Characteristics of an Algorithm
Not all procedures can be called an algorithm. An algorithm
should have the following characteristics −
· Unambiguous −
Algorithm should be clear and unambiguous. Each of its steps (or phases), and
their inputs/outputs should be clear and must lead to only one meaning.
· Input − An
algorithm should have 0 or more well-defined inputs.
· Output − An
algorithm should have 1 or more well-defined outputs, and should match the
desired output.
· Finiteness −
Algorithms must terminate after a finite number of steps.
· Feasibility −
Should be feasible with the available resources.
· Independent −
An algorithm should have step-by-step directions, which should be independent
of any programming code.
Algorithm example: Check whether a number is prime or not
Step 1: Start
Step 2: Declare variables n, i, flag.
Step 3: Initialize variables
flag ← 1
i ← 2
Step 4: Read n from the user.
Step 5: Repeat the steps until i=(n/2)
5.1 If remainder of n÷i equals 0
flag ← 0
Go to step 6
5.2 i ← i+1
Step 6: If flag = 0
Display n is not prime
else
Display n is prime
Step 7: Stop
Limitations of algorithm
Limited by the input: An algorithm
is limited by the input data it receives. If the input is incorrect or
incomplete, the algorithm may not be able to produce the desired output.
Limited by the complexity of the
problem: Some problems are so complex that no algorithm can solve them
efficiently. This is known as the computational complexity of the problem.
Limited by the computational
resources: Algorithms require computational resources such as memory and
processing power. If the resources are limited, the algorithm may not be able
to solve the problem efficiently.
Limited by the accuracy of the data:
Algorithms rely on accurate data to produce correct results. If the data is
inaccurate or contains errors, the algorithm may produce incorrect results.
Limited by the assumptions made:
Algorithms are often based on assumptions about the data or the problem being
solved. If the assumptions are incorrect, the algorithm may produce incorrect
results.
Limited by the time constraint: Some
problems require a solution within a specific time frame. If the algorithm
cannot produce a solution within the time limit, it may not be useful.
Limited by the programmer's ability:
The effectiveness of an algorithm is limited by the skill and experience of the
programmer who created it. A poorly designed algorithm may not produce the
desired results, even if the problem is well-defined.
Flow chart
A flowchart is
a type of diagram that represents a workflow or process. A flowchart can also be
defined as a diagrammatic representation of an algorithm, a step-by-step approach to
solving a task.
Example
find the HCF of two given numbers
Pseudo code:
to check whether a given number is prime or not
In computer science, pseudocode is a
plain language description of the steps in an algorithm or another system.
Pseudocode often uses structural conventions of a normal programming language,
but is intended for human reading rather than machine reading. It typically
omits details that are essential for machine understanding of the algorithm,
such as variable declarations and language-specific code.
Flag= 1, i=2
Read n
Repeat until i=(n/2)
If
remainder of n÷i equals 0
flag = 0
i =i+1
end if
end repeat
If flag = 0
Display n is not prime
else
Display n is prime
End if
////
Conditions in pseudo code
Pseudo code is a simple language
used to express the logic of a computer program algorithm. It is not a real
programming language, but it is used to describe the steps in an algorithm
using English-like statements. Here are some common conditions used in pseudo
code:
IF/THEN: This is used to check a
condition and execute a set of instructions if the condition is true.
Example:
IF x > 0 THEN
PRINT "x is positive"
END IF
IF/THEN/ELSE: This is used to check
a condition and execute one set of instructions if the condition is true, and
another set of instructions if the condition is false.
Example:
IF x > 0 THEN
PRINT "x is positive"
ELSE
PRINT "x is negative or
zero"
END IF
WHILE: This is used to execute a set
of instructions repeatedly while a condition is true.
Example:
WHILE x > 0 DO
PRINT x
x = x - 1
END WHILE
FOR: This is used to execute a set
of instructions a specified number of times.
Example:
FOR i = 1 TO 10 DO
PRINT i
END FOR
SWITCH/CASE: This is used to select
one of several sets of instructions to execute based on the value of a
variable.
Example:
SWITCH grade
CASE "A"
PRINT "Excellent"
CASE "B"
PRINT "Good"
CASE "C"
PRINT "Fair"
CASE "D"
PRINT "Poor"
CASE ELSE
PRINT "Invalid grade"
END SWITCH
Pseudo code loop
Loops in pseudo code
In pseudo code, loops are used to
execute a block of code repeatedly until a certain condition is met. There are
different types of loops, such as "for" loops, "while"
loops, and "do-while" loops, which can be used depending on the
specific use case. Here are some examples of how loops can be expressed in
pseudo code:
For loop:
for i = 1 to 10
// code to be executed
end for
This loop will execute the code
inside the loop body 10 times, with the value of i starting at 1 and
incrementing by 1 each time through the loop.
While loop:
while condition
// code to be executed
end while
This loop will execute the code
inside the loop body repeatedly as long as the condition is true.
Do-while loop:
javascript
Copy code
do
// code to be executed
while condition
This loop will execute the code
inside the loop body at least once, and then repeatedly as long as the
condition is true.
Nested loops:
for i = 1 to 10
for j = 1 to 5
// code
to be executed
end for
end for
This is an example of a nested loop,
where one loop is inside another. In this case, the code inside the inner loop
will be executed 5 times for each iteration of the outer loop, resulting in a
total of 50 executions of the inner loop code.