System Development Life Cycle (SDLC)

The systematic way of developing any software is called SDLC. It is the stepwise developing process. While developing the software various steps are evolved, all these steps form the life cycle of the system. Therefore, known as SDLC.

All these steps are:

There are different steps or stages of system development life cycle

1.       Problem Definition : - Problem definition is the most important stage of system or software development cycle. This is the stage where the development team studies the  present system. System analyst and other members are involved in this stage.

They are mainly discussed with the following issues:

-         Information of the present system and its working

-         Advantages and disadvantages of present system.

-         Collection the files, documents and reports of the present system.

-         Workload of the employees with present system

-         Need assistant.

2.       System Analysis : - Manual system is literally taken apart and examined piece by piece with the view of information need and other requirement of the management. The  responsibility of this stage goes to system analyst  who is involved in analyzing, designing, implementing and evaluating computer based information system to support the decision making and operations of an organization. to keep constant interaction with management, middle level manager , and working level personnel in order to achieve the logical and accurate perspective of the system. The aim of this stage is to ensure that all feasible alternatives and eventually product and to developed suggestions on how the goals may best be achieved.

3.       System Design : Programming and coding portion includes in this section. The various phases involved in the system design are:

a         Algorithm : -

b        Flowchart :-

c         Pseudo code :- It is the English statements of the program where some program related matters are written so that it becomes easy for the programmer to write the code later on.

d        Decision table: - Whatever the decision to be made on the program is written on the tabular format is known as decision table.

e        Decision tree: - Conversion of the decision table to the decision tree to make program easier.

f           DFD (Data Flow Diagram): - The pictorial representation of the data flow in the program.

g        Attributes, Entities, Tables and Database :-

h         ER-Diagram : - All the entities are to be showed by their relationship to other entities and this diagram is known as entity relationship diagram.

4. Coding and debugging

In this phase the concept is converted into the source code. After the coding is completed, it is tested, verified and debugged according to the programming rules.

Coding Rules :- There are various coding rules for different programming and it is done while program writing process.

Documentation: -  one of the most important phase which after coding phase 

-  Internal coding: it is prepared in order to understand the program itself by the programmer in the form of comment      or remarks.

-  External coding: made by the programmer to make the user understand how to use the system.

- Verification: this is the step which checks whether the program is working properly or not. Whether the desired output is obtained or not, this has been checked in this step.

- Code reading and review: it is the last step where the programmer goes through all the coding part and analyzes whether the code is without errors

5.       System development : - At this stage the final program specification and file design is handed over to the programmer will then translate the specification in programming language suitable for the purpose. Executable programs are output of this stage. The programmer should be able to select language and able to modify the programs. During this step the programmer translates the program logic design  documents into a computer language format.

6.       System testing :- In this phase it is analyzed that the software fulfills the objective of the development. According to the definition of IEEE it is defined as "the process of analyzing the software item to detect the difference between existing and required system." Another developer named Mayers defined the system testing as "the process of analyzing a program with the intension o finding out errors."

System testing methodologies are of two types:

a. Top down approach: Here the testing is done by the beginning from the main module and shifting towards the lower level modules. First the main module is tested and then it is broken down into sub modules, which is again tested and again broken into other sub modules. The process is repeated until the last module is tested.

b. Bottom up approach: It is just opposite of top down approach, where the lower level module is tested first and then shifted towards the upper level. In this model the lower module is tested and then they are integrated into some common modules and tested again. It is continued until the main modules has been obtained and tested.

These both testing can be divided into two parts. They are:

i.  White box testing: also known as "glass box testing", because the behavioral part or the structural part is tested here which is visible from the outside. It is used to check that the required specification has been met by the designed system or not.

ii.. Black box testing: here only the internal coding part is tested, so also known as "Functional testing". As we know that the code is written it is first of all tested by the developer to check whether it does the prescribed job or not. It is named as black box testing because only the hidden part is tested here.

7.       System Conversion : After new system has been tested, conversion to the new system occurs.

8.       System implementation : The implementation process runs form the point when the system design has been formally approved and new system is ready to  be used.

The following are major activities which involves in implementation process:

i)                     Change over the new system  :

ii)                   User training

iii)                  File conversion

9.       System evaluation : Once the implementation process is complete and the system is operational, the analyst must evaluate the new system. The purpose of the evaluation of the operation system is three-fold.

Firstly, the efficiency of the system is to be examined to see whether improvements ca  be made.

Second, the achievements of the system should be compared to the objectives originally proposed.

Thirdly, the evaluation provides valuable feedback to the system analyst.

10.   Delivery, maintenance and feedback: -This is the last step in SDLC. After final system is being developed, it is delivered to the market or installed in the user machines. The user now starts using the system and during the using period any problem arises, it is reported to the developer and the maintenance is done. User is the only parties by which the feedback has been collected and are improved and modified during another launching time

once the system becomes operational, management must address the issue of the security which includes.

Models

Some of the popular models to design the system development life cycle are as follows:

i. Waterfall model : - It is also known as the classical model which suggests the systematic and sequential approach to software development that begins at the system level and progresses through analysis, design, coding, testing and support.

The activities evolved in the water fall model are:

·        Feasibility analysis

·        Requirement analysis and project planning

·        System design

·        Detail design

·        Coding and unit testing

·        System and integration testing

ii. Prototype model: This is used when the developer are unsure about the detailed of the system to developed. In this case instead of developing the full system the sample or the part of the system is being developed. After the trial product is completed, both parties again sit together for discussion and lastly the final product is finalized. When the prototype is designed it is evaluated by the customer and used to refine requirements for the software to be developed. The steps involved in the prototype models are:

·              Requirements analysis

·              Design

·              Coding

·              Testing

iii. Iterative enhancement model: In this type of software development model the developer themselves provides the specification. Here no users are evolved, but the programmers itself makes a concept and launch it in the market. For example: Windows 95 and their grown up versions.

First version,  Second version ,  Third version and so on.

iv. Spiral model: This model is first enhanced by the scientist named "Boehm", it is the evolutionary software process models that couples the nature of prototyping with the controlled and systematic aspects of the water fall model. It contains six regions:

Customer communication: tasks required to establish effective communication between developer and customer.

Planning: tasks required defining resources, timelines and other project related information

Risk analysis: tasks required to access both technical and management risks.

Engineering: tasks required to build one or more representations of the application.

Construction and release: tasks required to construct, test, install and provide user support, e.g. documentation and training.

Customer evaluation: tasks required to obtain customer feedback based on evaluation of the software representations created during the engineering stage and implemented during installation stage.

Chapter 4 - Computer and Society

Computer are used in different sectors like banks, airlines, hospitals, colleges and universities, military, scientific research, entertainment, etc. where it provides better services because of computers. So, it is the source, a versatile machine fit to do the job at any place, any time. Thus, it has a great impact on our society. There are  some of the positive and negative impacts of computer in our society.

Positive Impact

1. Impact on Employment

ü  One can get new jobs like programming, system analyst, database administrator, software engineers, hardware engineers, graphics designers. etc

ü  Jobs in computer Manufacture and related companies.

2. Impact on Production

ü  Automated production is made accurate using technology like computers

ü  Used for assembling the hardware for example in car manufacturing companies

ü  Robotics makes production automatic and easier.

3. Information Sharing

ü  Information between two persons or two different organization can be shared via the computers i.e. internet

ü  Data and information can be accessed globally.

ü  Email, chat, video conferencing, etc. mechanism are used for sharing information.

ü  Electronic ads, billboards, bulletins and forums are placed in web to share information.

4. Impact on Education

ü  Computers are studied as a major subjects in universities and colleges

ü  Used as a teaching tools in science, health, etc.

ü  Used as a learning tools in practical class of school, colleges and universities.

ü  Online study is also available.

ü  Distant learning, using video conferencing, etc.

5. Impact on Business

ü  E-Commerce i.e. an electronic business is rising

ü  Online banking, effective shopping mall etc. have emerged

ü  Online book store, online gifts centers etc. are facilitating the consumers.

ü  Business is being global now a day

6. Impact on Entertainment

ü  Computers are used in video editing, special effects, animations, cartoon character movies, etc.

ü  They are used in music industry for composing, synthesizing, editing the music.

ü  Development of CDs and DVDs for better picture and sound quality.

7. Impact on Health Sector

ü  Computer controlled devices line CT-SCAN, ultra sound machine; MRI scan machine, etc. are used

ü  Used for keeping records of patients.

ü  Used for research and development

ü  Expert system line MYCIN is used in hospitals

8. Impact on Banking Sectors

ü  Computers are used in keeping information of computer's transactions, debit/credit, balance sheet, etc.

ü  Now-a-days electronic transaction is possible in banks

ü  ATM cards, debit/credit cards, etc. are used.

ü  Manual records are replaced by banking software.

9. Impact on communication sectors.

ü  Computers are used on communication fields like televisions, radio, FM stations, telecom, etc.

ü  Used for collecting news and information.

ü  Telex, emails, video conference, video phone, e-fax, etc.

Negative Impacts

1. Software Piracy

ü  Computers are used to copy the licensed software without the permission of owner.

ü  Internet is one of the sources of piracy where illegal copying of the programs is done.

2. Spreading Computer Viruses

ü  Computer viruses i.e. a parasitic program that infects another program may be spread through e-mails, floppy disks, computer to computer, etc.

ü  They can be used  to damage important files, slowdown the speed of computers, crash the system, etc.

ü  e.g. : Trojan horse, boot sector virus, cluster virus, worms, bombs, stealth virus, macro virus, joke program etc.

3. Theft

ü  Computer are used to steal the data from companies, government agencies which are used for some special purpose.

ü  Usually, hackers steals the secure data by invading the computer's password. Money is also transferred from on account to another.

4. Pornography

ü  Internet pornography is growing everywhere.

ü  Computers are used to view the adult websites thus making people offensive and sexual in their manners.

5. Plagiarism

ü  Computers are used to copy the other persons work, arts, notes, ideas, etc fro own purpose.

ü  Copying materials from others articles, books and pasting into ones needed place/ locations of article, books etc.

6. Hacking

ü  Hackers i.e. an expert programmers, intentionally gains the unauthorized access to other's computers.

ü  They invade the information system and destroy files and programs.

ü  They may send malicious programs.

7. Harassment

ü  Computers are used for irritating other people by sending insulting comments, focusing on gender and racism, making vulgar cartoons of others, treating people on basic of religion and nationality.

8. Unemployment

ü  Computers, somewhere is the cause of unemployment.

ü  Vacancies on newspaper at least recommend a computer literate.

ü  Computer technology replace the manual record keepers.

Ethics and Ethical Issues in Computing

ü  Do not use a computer to harm other people. Do not interface with other people's computer work. Donot snoop around in other peoples computer files.

ü  Do not use a computer to steal other's information.

ü  Do not use a computer to bear false witness.

ü  Do not copy or use properietary software for which you have not paid.

ü  Do not use other people's computer resources without authorization or proper compensation.

ü  Always think about the social consequences for the program you are writing or the system you are designing.

ü  Always use a computer in ways theat esure consideration and respect for your fellow humans.

Ethical  Standards.

A number of definitive sets of ethics have been developed to restrict the professionals in making harsh decisions and redirect them towards the right behavioral approach. Sofme of them include:

ü  Association for computing Machineryu (CAM) codes of ethics is a four point standard that vogoverns the ethical behavior among the computer professionals.

ü  Uniform computer information transaction Act (UCITA) defines a set of standards related to the legal and ethical behavior during the computer contract process.

Cyber Laws

Cyber law is a new grouping phenomenon that includes the wide variety of political, social and legal issues related to the internet and www. As internet is growing rapidly in the cyberspace, cyber law is becoming the preferred environment of the word. Cyber law encompasses a wide variety of political and legal issues related to the Internet and other communications technology, including intellectual property, privacy, freedom of expression, and jurisdiction. Cyber law and computer ethics and used t control the growing computer crime in the cyberspace. Some of the laws related to cyber are:

1. Intellectual property law : - It presents a set of exclusive rights in relation to the manner in which specific idea or information is expressed . It denotes the definite legal rights that  the authors, investors and other Intellectual Property holders may hold an expertise. These  laws are designed to protect various forms of intangible subject matters like: -

Copyright  Exists in many computer related creative works like software, source code discovery etc.

Patent Right  exists in software and hardware task that lets the inventor to exploit the invention right for certain period of time.

Trademark is a distinctive  sign that distinguishes the products and software of one business from that of another.

Industrial design  rights protects the appearance of one business from that of another

A trade secret is confidential information related to the work procedure of the organization.

Computer Crime Law

As the vast use of computers in business , education and personal use is expanding almost like nothing else, similar is the case in computer crimes and cyber faults. Computer crime is growing fast because the evolution of technology is fast, but the evolution of law is slow. While only limited number of nations has passed laws related to computer crime, the situation is an international problem that requires a long term solution. Protection measures such as hardware identification, access control software, disconnecting critical bank applications etc should be developed. However, compute4rs don't commit crimes; people do, proper ethical and moral standards should be acted out to reduce the probabilities of fraud.

Digital Signature

A digital signature is an electronic signature that is used to authenticate the identity of the sender of a message or the signer of a document, to ensure that the original content of the message or document is unchanged. It is a security system which consists of two. Keys: Private key and public key.

Personal Privacy Law

Privacy is the ability of an individual or group to stop information about themselves from becoming known to people other that those whom they choose to give the information. Sometimes it may be voluntarily sacrificed, normally in exchange for perceived benefits, very often with specify dangers and losses.

Cyber Law 2061 BS-Nepal

Nepal started its milestone journey in IT development in 2061 B.S. After approval from the cabinet, the much awaited IT landmark, The Cyber Law 2061 B.S., also known as the Electronic Transaction and Digital Signature Act(ETDSA) was released on 2061 B.S.

The law has number of positive provisions. As per the new law, activities such as hacking, deleting information, stealing document and software, pasting wrong information and improper and illegal materials would be brought under cyber-crime.

After introducing this law, the government can punish cyber criminals - both an individual or intuitional with up to five years of imprisonment and a fine of up to Rs. 50000 of both - based on severity of their crime. Before introducing this law, government was dealing with cyber crimes. under the public act.

Chapter 5 - State of art in computer technology

As we know the most fast changing technology is the computer technology. AI, Internet, multimedia etc are the present days technology.

Multimedia

It is a combination of two or more media such as text, graphics or sound. All the tv show is an example of multimedia. Basically a computer system with the capabilities to capture, digitize, compress, decompress and present information is multimedia system.

Role of multimedia

           

Multimedia tools

Text: It is one of the basic tools of multimedia, where the text can be displayed in different format. This also includes both unformatted text , formatted text with numbers etc.

Hypertext: It creates a link to another page. In hypertext document, the content is organized in tree structure. Each node in the tree is called the page. Each hypertext page hot words that hint the additional information. Hot words can respond to the user. When user click on the hot words or the hot spots , the user will be escaped from one topic to another.

Hypermedia: Hypermedia consists of hypertext combined with still or moving images. It requires the software to hypermedia that makes the presentation attractive. It requires a large input of data for audio, video and animation, for which a large amount of space on the ROM is needed.

Graphics and images: images can be defined as a static representation, this includes computer generated images, comprising lines, circles , curves and digitized images of documents.

Simulation: It is a process that tries to reproduce real world events or processes under controlled laboratory conditions.

Animation: Animation is one of the important tools of multimedia presentation. Animation refers to moving of graphics. Animation on multimedia presentation is the series of images that displayed in rapid succession, which give illusion of movement.

                        Computer animation is created by projecting still pictures, called cells, one after another at the rate of 30 per second. When the cells are projected fast enough, the illusion will be smooth motion. Computer animation also done by projecting a series of still images called frames. Using animation software as AutoCAD, 3D studio Max etc we can animate or mix up more than one image frames.

Video: This includes short sequences of moving images known as video clips and by combining all these clips together we can get full movie.

Sound: To make any of the presentation more effective sound is used. The sound we hear is analog signals and are digitized and stored in the disks like other data. Some of the things become useless without sound, such as: presentation of the heart beat.

2D animation: It is also known as pixel based or cell animation, where flat images are presented with two views (length and breadth).

3D animation: It is also similar to 2D but the only difference is that , in this case real images are created, i.e. length, breadth as well as depth are shown of a element.

Application of multimedia

1.       Multimedia in entertainment: One of the most important fields of multimedia is entertainment. Initially multimedia is used for computer games but now days it is extensively used for movie making.

2.       Multimedia in edutainment: It is also known as educational entertainment. Many games with the purpose of learning are used in the recent days with the help of multimedia.

3.       Multimedia with new software: Software has become one of the drastic changing technologies of the recent developed system. Each and every companies that were using different types of software were also been using the multimedia along with the particular software, so that it become easy for the user to use and understand.

4.       Multimedia in education: Huge growth of multimedia has been made in the field of education for both teacher as well as students. Various information are kept in different sites so that just typing the name of the particular sites one get information related with it.

5.       Multimedia in production and sales: In order to enhance the production as well as the sales of the goods different types of multimedia and graphics are used to make the advertisement attractive. It is done to promote the market of the products.

6.       Multimedia in web page: In the very first stage when the web pages were introduced, it is in the form of text only which is not so effective. But the multimedia has changes the face of the web page.

7.       Videoconference: One of the important applications of multimedia is video conference, which is done if any meeting has to be performed from various parts of the places. If any discussion, sharing of the views and ideas, planning for the projects, making presentation etc have to be performed from far distance, it is possible only by the help of video conferencing in Internet, which is very effective with the help of multimedia to make the video conferencing more effective.

E- Commerce

 E-commerce is broadly defined as the use of telecommunication or wide area networking to carry out financial transactions. With the help of e-commerce one can make a great deal of online shopping, banking, reservation in hotels as well as air tickets and theatre tickets, hire car. One can also buy and sell shares and also can apply for the distant learning buy making the payment sitting at home.

Artificial Intelligence (AI)

AI is the term which consists of different fields from machine vision to the expert system. Machine vision is the process of performing the tasks by the machine. Expert system is the software which utilizes the knowledge base collected from human specialist in certain area and helps user refer to this expertise in making their own decision.

            In case of AI, basically it has knowledge base and programming technique.

Basic applications of AI

Game playing: In case of logical games such as chess and many more, there are some functions of AI related. That can be calculated by the volume of the game we are using.

Understanding natural languages: Computer can able to understand the machine level language, which is also some sort of AI implementation.

Expert system: One of the very famous techniques of the AI is Expert System. Here the knowledge engineer interviews the expertise of the particular field and feed their knowledge in the computer for some specific tasks.

Chapter 6 - Object Oriented Programming (OOP)

The major objective of the development of OOPs is to overcome the flaws related with procedural languages.

Some of the striking features of OOP are:

• Emphasis on data rather than procedure.
• Programs are divided into what are known as Objects.
• Data structures are designed such that they characterize the objects.
• Objects may communicate with each other through functions.
• New data and functions can be easily added whenever necessary.
• Follow bottom up approach in program design.

OOP is the most recent concept among programming paradigm and still means different things to different people. We define OOP as "OOP is an approach that provides a way of modularizing programs by creating partitioned memory area for both data and functions that can be used as templates for creating copies of such modules on demand".

Basic concepts of OOPs are:

Object oriented programs have following concepts:

1.       Objects

2.       Classes

3.       Data abstraction

4.       Data encapsulation

5.       Inheritance

6.       Polymorphism

7.       Dynamic binding

8.       Message passing

1.       Objects: It is considered as basic runtime entities in an object oriented system. This may represent a person, a place, a bank account, a table of data or any item that the program must handle. When a program is executed, the objects interact by sending message to one another. For example "customer" and "account" are two objects in a program, then the customer object may send a message to the account object requesting for the bank balance. Each object contains data and code to manipulate the data. Objects can interact without having to know details of each other's data or code. It is sufficient to know the type of message accepted and the type of response returned by the objects.

2.       Class: A class is a collection of objects of similar type. For example: mango, apple, orange are the member of class fruit. Basically, class is a description of the object's attributes.

3.       Data abstraction and Encapsulation:

      Wrapping up of data and functions into a single unit (called class) is known as encapsulation. Data encapsulation is a most striking feature of a class. The data is not assessable to the outside world and only those functions which are wrapped in the class can access it. These functions provide the interface between the object's data and the program. This insulation of the data from direct access by the program is called data hiding.

      Abstraction refers to the act of representing essential features without including the background details or explanation. Classes use the concept of abstraction and are defined as a list of abstract attributes such as size, weight and cost and functions to operate on these attributes. They encapsulate all the essential properties of the object that are to be created. Since the classes use the concept of data abstraction, they are known as Abstract Data Types (ADT).

4.       Inheritance: It is the process by which objects of one class acquire the properties of the object of another class. It supports the property of the hierarchical classification. For example: the bird Robin is a part of class flying bird which is again a class of bird. The inheritance gives us an idea of reusability. It is always nice if we could reuse something that already exists rather than creating the same all over again. It save time as well as money and also increase reliability. C++ supports the same properties, as once a class has been written and tested, it can be used at the next time when required. This is usually done by creating the new class and reusing the properties of the existing one. The mechanism of deriving the new class from the old one is called inheritance or derivation.

The derived class inherits some or all of the traits from the base class

5.       Polymorphism: It is also another important OOPs concept. Polymorphism means the ability to take more than one form. Fro example: Shape, it gives us an idea of different types of construction, such as circle, rectangle, triangle etc. In this way we can say that polymorphism plays an important role in allowing objects having different internal structures to share the same external interface. In order implement the inheritance, polymorphism is basically used.

6.       Dynamic binding: Binding refers to the linking to a procedure call to the code to be executed in response to the call. Dynamic binding means that the code associated with a given procedure call is not known until the time of call at runtime. It is associated with the inheritance and polymorphism.

7.       Message passing

An object oriented program consists of a set of objects that communicate with each other. Objects communicate with one another by sending and receiving information much the same way as people pass message to one another. The concept of message passing makes it easier to talk about building systems that directly model or stimulate their real world counter parts.

   The message for an object is a request for execution of procedure and therefore will invoke a function in the receiving objects that generates the desired result. Message passing involves specifying the name of the object, the name of the function and the information to be sent.

Benefits of OOPs

·        Through inheritance, we can eliminate redundant code and extend the use of extending classes.

·        Software complexity can be easily managed.

·        Object oriented systems can easily upgrade from small to large systems. 

·        It is easy to partition the work in a project based on objects.

Chapter 7 - 'C' Programming

'C' is a programming high language. It is also called middle level language because it combines elements of a high level language with some features of assembler. A high level language tries to give programmer everything through built-in the language. A low-level language forces programmer to define function directly from the user language. It is developed and written by Dennis Ritchie at Bell Telephone Laboratories in U.S.A. in 1972,

 It is structured programming language. The important features of the structure programming language is that it uses blocks. A block is a set of statements that are logically connected. Structure programming also supports loop structure, such as do.while, for etc.

Character Set

'C' can supports all characters from the keyboard. There are mainly three types of character sets in 'C'

1.         Alphabet [ A to Z or a to z]

2.         Numbers [0 to 9]

3.         Special Symbols ( !, @, #, $, %,&,*, ^  etc.)

C Tokens

In a C source program, the basic element recognized by the compiler is the token. Token is the smallest individual unit in a program. In any programming language, a program is made up of individual syntactic elements, called tokens. These include identifiers, keywords, constants and variables, operator.

Identifiers :

Names given to various program elements such as variables, functions, labels, and other user defined items is known as identifier. It can be a combination of letters, digits and underscore(_), in any order.

Keywords

Keywords are the special words reserved by the compiler. These are also called reserved words. We cannot use these words as a variable name. There are mainly 32 keywords in 'C'. These are given below:

int         float      double  long      sort       unsigned          void      if           else      case     do        while     for        far default            struct    union    char      switch    static                return    signed  auto     break    const   continue goto    register 

typedef enum    near      extern

Data Types

Data type refers what types of data can be stored in a particular variable. There are different type of data types in C. In 'C' we define data type before the variable.

Example,   int  x ;                      char name;                    float salary;

Data Types	Description	Format	Size in byte	Range
Char	Character	%c or %s	1	0  - 255
Int	Integer number	%d	2	-32768 to 32768
long int	long integer or long number	%ld	4	-4294967296 to 4294967295
short int	integer or short number	%d	2	-32768 to 32768
unsigned int	unsigned integer`	%u	2	0 to 65535
Float	single precision point	%f`	4	6 digit decimal
Double	double precision point	%lf	8	12 digit decimal

Here int, char and float are the data types and x, name and salary are the variable.

Variables

Variables are the most fundamental parts of any programming language. Variable is a symbolic name which is used to store different types of data in the computer's memory. When the user gives value to the variable, the value is stored at the same location occupied by the variable. Variables may be of integer, character, string, or floating type.

Rules in variable

1.       Variables name must be less than equal to 8 characters

2.       The point and space not allowed in variable name.

3.       Variable name must start with alphabet.

4.       Instead of point or space you type underscore( _ ).

5.       If you type capital letter in variable name then all statement you have to use same case.

Rules of doing programming

1. The header file must  be included before main according to the library functions which are used in the statement.
2. The program starts with main( ) . It is a user defined function which runs the program.
3. The program statements starts with middle bracket( { ) and ends with middle brackets  ( } ).
4. Each of the statement of the C program ends with semicolon ( ; )
5. The functions, keywords or commands must be in small letter.