الرحيمالرحمنهللابسم

Assalam o Alaikum!

Software Programming and DevelopmentPresented to: Waqar Azeem

Presented by: M. Haseeb Akhtar BSCS-(14-32)

Asadullah BSCS-(14-25)

Farwa Shabbir BSCS-(14-09)

Hiba Amjad BSCS-(14-22)

Wasfa Aslam BSCS-(14-07)

Maria Asif BSCS-(14-23)

University of Gujrat

Lahore Campus

Introduction to Computers and Technology

Table of Content

Introduction

Definition

Hardware, software and interaction between the them.

Code and Machine Code

Programming Languages

Language Translators

Planning a computer program and problem solving

Object-orientated programming

File and its types

Introduction:Software development is a complicated process. It requires careful planning

and execution to meet the goals. Sometimes a developer must react quickly

and aggressively to meet ever-changing market demands. Maintaining

software quality hinders fast-paced software development, as many testing

cycles are necessary to ensure quality products.

Definition:A computer program is a set of instructions or statement to be carried out by

the computer. It is a set of step by step instructions that directs the computer

to do the tasks you want it to do and produce the results you want.

There are at least two good reason for learning programming:

Programming helps you understand computers.

Writing a few programs increases your confidence level.

Hardware:

Computer Hardware is the collection of physical parts of the computer system.

Main examples of hardware are:

Motherboard

Processor

Hard drive

RAM etc.

Software:

Software is a set of instruction that makes the computer to perform task. In

other words software tells the computer what to do.

It also creates an interface between

computer hardware and user.

Type of Program Input What the Program Does Output

Word processor Characters you type from

the keyboard

Formats the text; corrects

spelling etc.

Displays and prints neatly

organized text

Interaction between Software and

hardware:

Hardware and software are inter-related.

User inputs the instruction of data into the computer with the help of

software.

Computer hardware doesn’t know what action to be performed on that

instruction without software.

Code:

A set of symbols and mnemonics for representing something. For example,

most computers use ASCII codes to represent character.

In programming, code is of two types:

Source code:

It is the list of commands to be assembled or compiled into an executable computer

program.

Object code:

It refers to the code produced by the compiler or assembler.

Machine Code:

Machine code, also called machine language, is a computer programming

language consisting of binary or hexadecimal instructions which can be

directly executed by the computer.

It is the language into which all programs

must be converted before they can

be run.

Programming Languages:

The language used to write a program is called programming language.

it is the way of creating set of instructions.

Creates a source code.

Types of Programming Languages

Low-level High-level

Types of Programming Languages:

Low Level Languages:

Instruction given to the computer in the binary form.

It is further divided into two types.

Low-Level Language

1st Generation 2nd Generation

1st Generation Language:

1st generation language is also known as Machine language.

By using machine language, a programmer creates instructions in the form

of binary codes (i.e. 1’s and 0’s).

2nd Generation Language:

2nd generation language is also called assembly language.

It uses simple phrasing in place of the complex series of binary numbers,

used in machine language.

To develop a software with it, a programmer uses text editor for source files.

A special translator program is used to convert source files into object code.

This special translator program is called assembler, that converts assembly

language instructions into machine language.

High-level Languages:

It is the language that is easily understood by the humans and written in the

form of human friendly manner.

It consists of different functions to create a program.

It is divided into three categories.

High-Level Language

3rd Generation 4th Generation 5th Generation

3rd Generation Languages:

There are four languages that are categorized in 3rd generation languages.

These four languages are:

C

C++

Java

ActiveX

C Language:

C is a powerful language that is used to create programs with fast and

efficient code.

It is extremely popular with professional developers.

C compiler is used to compile or translate code written on it into machine

readable form.

Turbo C is a common example of C compiler.

C++ Language:

C++ is an object oriented implementation of C.

It is an extremely efficient and powerful language.

It also uses C compiler for the same purpose as C language.

Turbo C is used for compiling both C and C++ language.

Java:

It creates cross-platform programs.

Java enables web page designer to include small applications called

applets in web pages.

It creates self-contained functions.

ActiveX:

It is Microsoft’s answer to java.

It can create signed applications that has been verified as being safe to

run on a computer.

It can also create self contained functions.

4th Generation Languages:

4GL uses text environment or visual environment.

In text environment, the programmer uses English text or word.

In visual environment, the programmer uses toolbar to drag items like labels,

test boxes and buttons to make an application.

4GL includes:

.NET

Authoring Environment

Sun Studio One

.NET:

It is Microsoft’s newest entry.

It combines several programming languages into one IDE.

For example, Visual basic, C++,C# and J#.

Programs can be written for windows, www and pocket pc.

Authoring Environment:

Authoring environment consists of special programming tools to create:

Multimedia

Applications

Web pages (e.g. Macromedia Director)

It includes its own language which is called scripting language.

Sun Studio One: It is used to for java for visual editing.

It is developed by sun, the creators of Java.

5th Generation Language:

In principle, a 5GL would use artificial intelligence to create software based

on description of what the software should do.

This type of system is proving more difficult to invent than the code it was

intended to create.

It is basically a conceptual language.

Language Translators:

For converting the source code into object code, translators or converters

are used.

These translators are of three types:

Assembler

Compiler

Interpreter

Assembler is not commonly used, so we’ll only discuss the compiler and

interpreter.

Compiler:

Translates the whole program at a time.

Common reason to convert all the source code into object code is to

creating an executable file.

Each programming language requires its own compiler to translate code

written in that language.

For example, the programming language C++ requires a C++ compiler,

while the language Pascal requires a Pascal compiler.

The source code is translated into object code successfully with the help of

compiler if it is free of errors.

If there is any error in the source code, the compiler identifies the error at the

end of the compilation.

The error must be removed for successful compilation.

Interpreter:

translates the source code into machine code statement by statement is

called interpreter.

Translate one line at a time and executes it.

if an error comes, translation process will be terminated.

Makes it easier to detect and remove errors in the source program.

It is a time consuming process of translating and executing statement one

by one.

Each time the program is run, the source code is translated again, and for

this purpose you must have a translator program (interpreter) permanently

in your computer.

Basic difference between Compiler

and Interpreter:

Compiler Takes the entire

program as an input

Interpreter takes single

instruction as input

Basic difference between Compiler

and Interpreter:

Program execution is

very fast.

Program execution is

very slow.

Basic differences between Compiler

and Interpreter:

It is difficult to trace a

problem in compiler.

It is easy to trace a

problem in interpreter due

to line by line interpreting.

Basic differences between Compiler

and Interpreter:

Errors are displayed

after the entire program

is checked

Errors are displayed for

every instruction

Planning a Computer Program and

problem solving:

Planning means creating an image about what will you do in future.

In computer programming, it means creating an image about how you will

create a specific program.

Planning and problem solving of a computer program can be divided into

three types:

Algorithms

Flow Charts

Pseudo Codes

Algorithms:

It is a set of well defined instructions in a sequence to solve a problem.

An Algorithm should have:

A clear starting point.

Precisely defined input/output parameters.

Clear processing steps.

A clear stopping point

It should not have computer code, instead, it should be written in simple and

efficient format, which can be used in writing a code.

It is written in a format that is closer to high-level language.

For example: Algorithm of Addition of two numbers

Step 1: Start

Step 2: Declare variables number1,number2 and sum

Step 3: Read values

Step 4: Add number1 and number2 and store in sum

Step 5: Display sum

Step 6: Stop

Flow Charts:

It is a visual representation of an Algorithm.

You can also say that is the diagrammatic representation of an algorithm.

Importance of Flow chart:

Using flow chart technique, the sequence of program can be easily determined.

It is used to convert algorithm in simple program flow form.

Different symbols are used to show the flow of program

E.g.:

Start or

StopConditions

Flow

Flow chart of Addition of two numbers:

Start

Declare number1,

number2 and sum

Read values

Sum=number1+nu

mber2

Display

Sum

Stop

Pseudo Codes:

It is a simple way of writing a program code in a syntax closer to high-level

language.

It does not use program language syntax.

It is a simple phrase to plan our program before we actually develop a

program.

A Pseudo code:

helps to understand the program easy way.

Is easy to understand.

Is generally short and precise.

can be easily detectable to the mistakes and errors.

Pseudo code for addition of two numbers:

A number1

B number2

S sum

Start

Display: enter two numbers

Read: Read numbers

Add: S=A+B

Display: sum, S

Stop

That was all about software programming

and development….

Thank you for you support