Introduction to computer programming

INTRODUCTION TO COMPUTER
PROGRAMMING
Dr. SANGHEETHAA.S
ASST.PROFESSOR
DEPT . OF ELECTRICAL AND COMPUTER ENGG

INTRODUCTION
• COMPUTER
– WHAT IS A COMPUTER?
– PARTS OF A COMPUTER?
- HARDWARE
INTERNAL
EXTERNAL
-SOFTWARE
SYSTEM
APPLICATION

COMPUTER
• AN ELECTRONIC DEVICE
• Helps us to solve problems according to a set
of instructions, or programs
• To do our work fast, easy
• Saves time and energy
• Can hear music, watch movies, paint pictures,
solve complex problems, entertainment,
infotainment, etc..

Hardware - Hardware refers to the parts of a computer
that you can see and touch, including the case and everything
inside it
• External
– Monitor
– Printer
– Scanner
– Speaker
– Microphone
– Mouse
– Keyboard etc

Internal
• Motherboard
• CPU - microprocessor. It's the "brain" of your
computer—the part that translates
instructions and performs calculations
• Power supply
• HDD
• Graphics card
• Modem card etc

Software - Software refers to the instructions, or
programs, that tell the hardware what to do – machine readable
instructions
• System software
– Compiler
– Linker
– Interpreter
– Loader
– OS
• Application software
– Free and open source
– copyrighted

CRT Display
Keyboard
Mouse
“The Box”
CD-ROM Drive
Floppy
Disk
Drive

SIMM
(Single Inline Memory Module)

Schematic Diagram of a Personal
Computer...

Ports
CPU
RAM
Disk
controller
Graphics
card
Sound
card
Network
card
Printer
Mouse
Keyboard
Modem Monitor
Speakers
bus
Computer

Introduction to computer programming

Tutorial
• What are the types of computers?
• What are the uses of computers?
• What are the input devices you know?
• Write about the working of the input devices?
• Write about the working of output devices?

PROGRAMMING BASICS
• Programming language - main purpose of
programming languages is to provide instructions
to a computer
– Low level - Computers only understand one language
and that is binary language
– Assembly language - ADD A, B – adds two numbers in
memory location A and B
– The assembly language must be translated to machine
code by a separate program called assembler. Thus
assembly languages are unique to a specific computer

High level
• High-level languages are more English-like and,
therefore, make it easier for programmers to "think" in
the programming language. High-level languages also
require translation to machine language before
execution. This translation is accomplished by either a
compiler or an interpreter. Compilers translate the entire
source code program before execution. Interpreters
translate source code programs one line at a time.
• FORTRAN (FORmula TRANslator), BASIC (Bingers
All Purpose Symbolic Instruction Code), PASCAL,
C, C++, Java are some examples of high-level
languages.

Programming Paradigm
• provides the programmer's view of code execution.
• Procedural Programming Languages
• Procedural programming specifies a list of operations
that the program must complete to reach the desired
state. Each program has a starting state, a list of
operations to complete, and an ending point. This
approach is also known as imperative programming.
Integral to the idea of procedural programming is the
concept of a procedure call.
• Example : are FORTRAN and BASIC.

Structured Programming Languages
• Structured programming is a special type of
procedural programming
• programmers break program structure into
small pieces of code that are easily
understood. It also frowns upon the use of
global variables and instead uses variables
local to each subroutine.
• Examples : C, Ada, and Pascal.

Object-Oriented Programming
Languages
• the designer specifies both the data structures
and the types of operations that can be applied
to those data structures
• This pairing of a piece of data with the operations
that can be performed on it is known as an
object. A program thus becomes a collection of
cooperating objects, rather than a list of
instructions. Objects can store state information
and interact with other objects, but generally
each object has a distinct, limited role.

Algorithm
• An algorithm is defined as a step-by-step
sequence of instructions that must terminate
and describe how the data is to be processed
to produce the desired outputs.
• Simply, algorithm is a sequence of
instructions.
• Algorithms are a fundamental part of
computing.

Tools – to document program logic
• flowcharts, structured chart, and Pseudocode
• Pseudocode (derived from pseudo and code)
is a compact and informal high-level
description of a computer algorithm that uses
the structural conventions of programming
languages, but typically omits detailes such as
subroutines, variables declarations and
system-specific syntax.

Example:
• Original Program Specification:
• Write a program that obtains two integer
numbers from the user. It will print out the sum
of those numbers.
• Pseudocode:
• Prompt the user to enter the first integer
Prompt the user to enter a second integer
Compute the sum of the two user inputs
Display an output prompt that explains the
answer as the sum
Display the result

Structured Charts
• Structured chart depicts the logical functions to
the solution of the problem using a chart. It
provides an overview that confirms the solution
to the problem without excessive consideration
to detail. It is high-level in nature.
• Example: Write a program that asks the user to
enter a temperature reading in centigrade and
then prints the equivalent Fahrenheit value.

Example
centigard
centigard
CelsusToFarh
(main func)
InPutCen CalcFar OutPutFar
Fahrenheit

Flowchart
• A flowchart (also spelled flow-chart and flow
chart) is a schematic representation of an
algorithm or a process . The advantage of
flowchart is it doesn’t depend on any
particular programming language, so that it
can used, to translate an algorithm to more
than one programming language. Flowchart
uses different symbols (geometrical shapes) to
represent different processes. The following
table shows some of the common symbols.

• Example 1: - Draw flow chart of an algorithm
to add two numbers and display their result.
• Algorithm description
• Read the rules of the two numbers (A and B)
• Add A and B
• Assign the sum of A and B to C
• Display the result ( c)

Start
End
Read A, B
C= A+B
Print C

Example 2: Write an algorithm description and draw a flow chart to check a
number is negative or not.
Algorithm description.
1/ Read a number x
2/ If x is less than zero write a message negative
else write a message not negative

• Example 3: - Write the algorithmic description and
draw a flow chart to find the following sum.
• Sum = 1+2+3+…. + 50
• Algorithmic description
• 1. Initialize sum too and counter to 1
– If the counter is less than or equal to 50
•
– • Add counter to sum
– • Increase counter by 1
– • Repeat step 1.1
– Else
• • Exit
•
• 2. Write sum

System Development Life Cycle (SDLC)
• The Systems Development Life Cycle (SDLC) is
a conceptual model used in project
management that describes the stages
involved in a computerized system
development project from an initial feasibility
study through maintenance of the completed
application.

Feasibility study
• The first step is to identify a need for the new system.
components:
• Organizational Feasibility
– How well the proposed system supports the strategic objectives of the
organization.
• Economic Feasibility
– Cost savings
– Increased revenue
– Decreased investment
– Increased profits
• Technical Feasibility
– Hardware, software, and network capability, reliability, and availability
• Operational Feasibility
– End user acceptance
– Management support
– Customer, supplier, and government requirements

Requirements analysis
• Requirements analysis is the process of
analyzing the information needs of the end
users, the organizational environment, and
any system presently being used, developing
the functional requirements of a system that
can meet the needs of the users.
• Also, the requirements should be recorded in
a document, email, user interface storyboard,
executable prototype, or some other form.

Designing solution
• After the requirements have been
determined, the necessary specifications for
the hardware, software, people, and data
resources, and the information products that
will satisfy the functional requirements of the
proposed system can be determined.

Testing designed solution
• A smaller test system is sometimes a good
idea in order to get a “proof-of-concept”
validation prior to committing funds for large
scale fielding of a system without knowing if it
really works as intended by the user.

Implementation
• The real code is written here. Systems
implementation is the construction of the new
system and its delivery into production or day-
to-day operation.
• The key to understanding the implementation
phase is to realize that there is a lot more to
be done than programming. Implementation
requires programming, but it also requires
database creation and population, and
network installation and testing.

• Unit testing
• Integration and System testing
• Maintenance
• What happens during the rest of the
software's life: changes, correction, additions,
moves to a different computing platform and
more. This, the least glamorous and perhaps
most important step of all, goes on seemingly
forever.

Introduction to computer programming

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Introduction to computer programming