Development Of A Student Payment System Computer Science Essay

Earlier than acquiring into sketch the diagram we want to construct up the indispensable imposter codification for the specified inquiry. If non it will be difficult to happen the constituents in functional list every bit good as status list. Before study imposter codification we need to descry the entities that are traveling to participates. So they are,

StudentNo

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Stu-Name

CourseFee

Paid

Balance

This is the imposter codification for the pupil payment system

Get down

Open the file

Read a record

Count=0 While Not EOF

If due & gt ; 0 so

Print StudentNo, StName, Balance

Count=count+1

End if

Read a record

Display count

End

This is the illustration for the imposter codification. Here I have used Count to Count the figure of pupils those who have outstanding balance for the class. With the aid of this pseudo codification following tabular array is produced

Functional List

Condition List

Start

While NOT EOF

Open the file

{

Read a record

( 1 ) if due & gt ; 0 so

Count=0

{ ( 5 ) , ( 6 ) }

Print StudentNo, StuName, Balance

( 3 )

Count=count + 1

}

Display Count

Stop

This a functional and condition list tabular array for the above mentioned scene. Under maps list refer what are the maps happened in the peculiar system. Condition list refer to complete the procedure what are the status is traveling to utilize for the peculiar system.

With the aid of the imposter codification and functional and condition list table we can make the construction diagram for the above mentioned scene.

STRUCTURE DIAGRAM FOR THE STUDENT PAYMENT SYSTEM

iˆ?

*

Get down

Body

End

Main

Main

Get down Body End

( 1 ) , ( 2 ) , ( 3 ) , ( 4 ) ( 1 ) ( 7 ) , ( 8 )

While

iˆ?

( 3 ) , ( 4 ) ,

IF ( 1 )

iˆ?

( 6 ) , ( 5 )

Structure Diagram ( 1.1 )

This is the construction diagram for the pupil payment system. Here the construction contains chief 4 parts. Those are Main, Begin, organic structure, and terminal.

Main: – Initiation of construction diagram

Begin: – It ‘s refers what are the maps begin the procedure.

Body: – Conditionss parts are coming under here.

End: – If the procedure finishes it will demo the consequences

Undertaking 1.2

I )

Pseudo codifications for pupil Markss system

Get down

Open the file

Read a record

While Not EOF

If Markss a‰? 80

Displaies “ Distinction ”

Else

if Markss a‰? 60

Display “ Credit ”

Else

if Markss a‰?40

Display “ Pass ”

Else

Display “ Fail ”

End if

End if

End if

Read a record

End While

End

This is the imposter codification for the pupil marks system. First if status gives the bid for the system if grade is higher than 80 the scaling should be Distinction. The 2nd if statement refers if the grade is higher than 60 and lower than 80, the scaling will be Credit. The 3rd if statement refers if the grade is higher than 40 and lower than 60 is coming under rating call Pass. The concluding status else refers balance Markss are coming under Fail scaling.

With the aid of pseudo codification we are traveling to make flow chart. Following sub undertaking contain the flow chart for the pupil grade system

( two ) Flow Chart

Functions are draw by the order. When conditions symbols comes it will make two ways either it can be true or autumn. If it ‘s true the procedure is finish. If it ‘s falls the remainder of the status may fulfill. When it ‘s fulfilling the status procedure will be finish. Following is the flow chart for pupil Markss system

if pupil Markss a‰? 60

if Student Markss a‰?40

Display “ fail ”

Read the record

Display

“ Base on balls ”

Open the file

Read the record

While terminal of file

If Student marks a‰? 80

Near file

Yes

Yes

Yes

Exit

Recognition

Display

“ recognition ”

Display

“ Differentiation ”

No

No

Yes

No

No

Undertaking 1.3 ( Use instance diagram )

Use instance diagram

This undermentioned undertaking we need to place the histrions those who are traveling to take part in the procedure. Followings are the footings use under the usage instance diagram

Actors: – they are the participants who create the procedure.

Box: – Box is a range of the system which refers the system boundaries and restrictions.

Sequence: – Sequence is the procedure inside informations which departures to go on amongst the histrions

Order System

Question

Order

Client

Confirm order

Gross saless adult male

Payment

Issue bill

Account clerk

Descriptions

Client: Topographic point an order with gross revenues individual

Account clerk: when order confirmed he or she issue the bill to the client

Gross saless adult male: Answer client question and accept the order

Question: Its made about the merchandise by client to gross revenues individual

Order: Its made by client with the gross revenues individual

Confirm order: Its made by gross revenues individual with client and history clerk

Issue Invoice: Its green goods by history clerk and issue to the client

Undertaking 2.1 ( Benefits of certification )

To accomplish ends

Effective direction requires the procedure being managed to be seeable. Because package is intangible and the package procedure involves seemingly similar cognitive undertakings instead than evidently different physical undertakings, the lone manner this visibleness can be achieved is through the usage of procedure certification.

Procedure certification falls into a figure of classs:

Plans, estimations and agendas these are paperss produced by directors which are used to foretell and to command the package procedure.

Reports these are paperss which report how resources were used during the procedure of development.

Standards these are paperss which set out how the procedure is to be implemented. These may be developed from organisational, national or international criterions.

Working documents these are frequently the chief proficient communicating paperss in a undertaking. They record the thoughts and ideas of the applied scientists working on the undertaking are interim versions of merchandise certification, describe execution schemes and put out jobs which have been identified. They frequently, implicitly, record the principle for design determinations.

Improve Communication

Memos and electronic mail messages these record the inside informations of mundane communications between directors and development applied scientists. The major feature of procedure certification is that most of it becomes outdated. Plans may be drawn up on a hebdomadal, biweekly or monthly footing. Progress will usually be reported hebdomadal. Memos record ideas, thoughts and purposes which change. Although of involvement to package historiographers, much of this procedure information is of small existent usage after it has gone out of day of the month and there is non usually a demand to continue it after the system has been delivered. However, there are some procedure paperss that can be utile as the package evolves in response to new demands. For illustration, trial agendas are of value during package development as they act as a footing for re-planning the proof of system alterations. Working documents which explain the grounds behind design determinations ( plan principle ) are besides potentially valuable as they discuss design options and picks made. Access to this information helps avoid devising alterations which conflict with these original determinations. Ideally, of class, the design principle should be extracted from the working documents and individually maintained. Unfortunately this barely of all time happens.

Accountability

Documentation demonstrates answerability by:

-Identifying the attention supplier ;

-Determining duty ; and

-Contributing to legal proceedings.

Accountability answers the inquiry, who did what and when? Documentation demonstrates a nurse ‘s answerability and determines duty. It besides resolves inquiries or concerns about the proviso of

attention. A user ‘s certification may be used in a legal proceeding, such as a case, medical examiner ‘s inquest or a subject hearing at the College.

To back up terminal users

Users of a system are non all the same. The manufacturer of certification must construction it to provide for different user undertakings and different degrees of expertness and experience. It is peculiarly of import to separate between end-users and system decision makers:

1. End-users use the package to help with some undertaking. This may be winging an aircraft, pull offing insurance policies, composing a book, etc. They want to cognize how the package can assist them. They are non interested

in computing machine or disposal inside informations.

2. System decision makers are responsible for pull offing the package used by end-users. This may affect moving as an operator if the system is a big mainframe system, as a web director is the system involves a web of workstations or as a proficient guru who fixes end-users package jobs and who liaises between users and the package provider. To provide for these different categories of user and different degrees of user expertness, there are at least 5 paperss ( or possibly chapters in a individual papers ) which should be delivered with the package system

2.2

Jackson Structured Programming

Jackson Structured Programming or JSP is a method for structured scheduling based on correspondences between informations watercourse construction and plan construction. The method is closely related in construct to making a parser for a regular look that describes the informations watercourse construction, but attempts to construct a plan construction that matches more than one information watercourse and provides counsel and techniques to counterbalance the limited expression in front and the clangs between the constructions of the different informations watercourses.

JSP was originally developed in the 1970s by IT adviser Michael A. Jackson and documented in his 1975 book Principles of Program Design. Jackson ‘s purpose was to better the general criterion of COBOL scheduling, but the method is still utile when coding with modern programming linguistic communications such as C and Perl. And while JSP was originally geared towards composing batch-style file processing plans, its rules are still utile when scheduling in the little, below the degree where object-oriented methods become of import.

As a method of scheduling, JSP is more straightforward than other structured methods, avoiding the springs of intuition needed to successfully plan utilizing, say, top-down decomposition. And although it imposes a construction upon a plan which improves its modifiability and maintainability, the construction is instead different from the type of construction advocated by Wirth, Dijkstra, et Al.

The method

JSP uses semiformal stairss to capture the bing construction of a plan ‘s inputs and end products in the construction of the plan itself.

The purpose is to make plans which are easy to modify over their life-time. Jackson ‘s major penetration was that demand alterations are normally minor pinchs to the bing constructions. For a plan constructed utilizing JSP, the inputs, the end products, and the internal constructions of the plan all lucifer, so little alterations to the inputs and end products should interpret into little alterations to the plan.

JSP constructions plans in footings of four constituent types:

* cardinal operations

* Sequences

* Iterations

* choices

The method begins by depicting a plan ‘s inputs in footings of the four cardinal constituent types. It so goes on to depict the plan ‘s end products in the same manner. Each input and end product is modeled as a separate Data Structure Diagram ( DSD ) . To do JSP work for compute-intensive applications, such as digital signal processing ( DSP ) it is besides necessary to pull algorithm construction diagrams — something non envisioned by Jackson himself.

The input and end product constructions are so unified or merged into a concluding plan construction, known as a Program Structure Diagram ( PSD ) . This measure may affect the add-on of a little sum of high degree control construction to get married up the inputs and end products. Some plans process all the input before making any end product, whilst others read in one record, compose one record and iterate. Such attacks have to be captured in the PSD.

The PSD, which is linguistic communication impersonal, is so implemented in a programming linguistic communication. JSP is geared towards procedural linguistic communications which are non OO, such as Fortran, Pascal, Cobol, PL/1 and C. To a big grade JSP is non helpful for OO linguistic communications and declaratory linguistic communications.

JSP uses a ploting notation to depict the construction of inputs, end products and plans, with diagram elements for each of the cardinal constituent types.

A simple operation is drawn as a box.

A box labeled ‘A ‘

An operation

Sequence

A sequence of operations is represented by boxes connected with lines. In the illustration below, operation A consists of the sequence of operations B, C and D.

A box labeled ‘A ‘ connected to three boxes below it labeled ‘B ‘ , ‘C ‘ and ‘D ‘

A sequence

Iterations

An loop is once more represented with united boxes. In add-on the iterated operation has a star in the top right corner of its box. In the illustration below, operation A consists of an loop of zero or more supplications of operation B.

A box labeled ‘A ‘ connected to a box labeled ‘B ‘ below it with a star in the top right corner

Iteration

Choice

Choice is similar to a sequence, but with a circle drawn in the top right manus corner of each optional operation. In the illustration, operation A consists of one and merely one of operations B, C or D.

A box labeled ‘A ‘ connected to three boxes below it labeled ‘B ‘ , ‘C ‘ and ‘D ‘ each with a circle in the top right manus corner

A choice

2.3

( I )

The intent of the compiler is to interpret the plans written in human clear linguistic communication to machine linguistic communication which is apprehensible to computing machine machine. A compiler reads direction in the plans and translates it, if there is any mistake it besides place it and warns about it to user. The mistake could be typing error ( syntax mistake ) or a logical mistake. when all the erros are removed the instructions are sent to the computing machine for processing

For executing different undertaking on the computing machine, a compiler is communication medium that translate beginning linguistic communication into mark linguistic communication. Compiler allows the user to execute customized undertaking on machine. Initially for composing compiler machine linguistic communication was used. After some development assembly linguistic communication and these yearss high flat linguistic communication are used for composing compiler. We need compiler because it allows us to pass on with hardware. It is besides usage to cover the “ GAP ” between Worlds and the computing machine linguistic communication. Computer can understand merely one linguistic communication that binary linguistic communication consists of merely two figures are 0 and 1.

Binary linguistic communication is besides called machine linguistic communication. When there is merely Machine Language so programmers write their compilers in this linguistic communication. But it is really hard and boring occupation. The function of compiler is take beginning codification written in high degree linguistic communication ( Java, C++ , VB.Net etc ) . The High Degree Languages are easy understood by worlds. So compiler converts the plan written in formal linguistic communication ( Source linguistic communication ) into machine linguistic communication ( aim linguistic communication ) . As we know that computing machines can easy understand machine linguistic communication. There are different plans related to compiler that works before digest such as editor, preprocessor, assembly program, linker or stevedore, debugger and profiler.

two.

Interpreter tool

An translator is a computing machine plan that executes other plans. This is in contrast to a compiler which does non put to death its input plan ( the beginning codification ) but translates it into feasible machine codification ( besides called object codification ) which is end product to a file for later executing. It may be possible to put to death the same beginning codification either straight by an translator or by roll uping it and so put to deathing the machine codification produced.

An interpreterA reads an feasible beginning plan written in a high degree programming linguistic communication every bit good as informations for this plan, and it runs the plan against the informations to bring forth some consequences. One illustration is the UNIX shell translator, which runs operating system commands interactively. The difference between construing and interlingual rendition is merely the difference in the medium: the translator translates orally, while a transcriber interprets written text. Both construing and interlingual rendition presuppose a certain love of linguistic communication and deep cognition of more than one lingua.

Beginning Code

Interpreter

Consequence

Interpreter reads the beginning codification

The consequences appears on the screen

Figure: 2.3.1 – Interpreter

2.4

Syntax mistakes in Java

… expected

The sentence structure of Java is really specific about the needed punctuation. This mistake occurs, for illustration, if you forget a semicolon at the terminal of a statement or do n’t equilibrate parentheses:

if ( I & gt ; j // Error, imbalanced parentheses

soap = I // Error, losing semicolon

else

soap = J ;

Unfortunately, this sentence structure mistake is non needfully caught exactly at the point of the error so you must carefully look into the predating characters in the line or even in a old line in order to happen the job.

Eclipse:

Syntax mistake, infix “ ) Statement ” to finish IfStatement

Syntax mistake, insert “ ; ” to finish Statement

Eclipse is more enlightening as to the precise sentence structure mistake encountered.

unclosed twine actual

Stringing misprints must be enclosed in citation marks.1 This mistake occurs if you fail to end the actual with citation Markss. Fortunately, the sentence structure of Java requires that a string actual appear wholly on one line so the mistake message appears on the same line as the error. If you need a string actual that is longer than a individual line, make two or more misprints and concatenate them with + :

Stringing longString =

“ This is first half of a long twine “ +

“ and this is the 2nd half. “ ;

Eclipse: String misprint is non decently closed by a double-quote In Eclipse you can compose a string misprint of arbitrary length and the environment will interrupt the twine and infix the + automatically.

illegal start of look

Most programming concepts are either statements or looks. This mistake occurs when an look is expected but non found. In Java, an assignment statement is considered to be an look which returns a value, so mistakes refering looks besides apply to assignment statements.2 Examples:

An excess right parenthesis after the status of an if-statement:

if ( I & gt ; J ) ) // Error, excess parenthesis

soap = I ;

Eclipse: Syntax mistake on token “ ) ” , cancel this token3 Eclipse diagnoses this as a simple sentence structure mistake and does non advert looks.

Forgeting the right-hand side of an assignment statement:

soap = ; // Error, losing right-hand side

Eclipse: Syntax mistake on nominal “ = ” , Expression expected after this item

non a statement

This mistake occurs when a syntactically right statement does non look where it should. Examples:

aˆ? Writing an assignment statement without the assignment operator:

aˆ? soap ; // Error, losing =

Eclipse: Syntax mistake, insert “ AssignmentOperator Expression ” to finish Expression

aˆ? Misspelling else:

aˆ? if ( I & gt ; J )

aˆ? soap = I ;

aˆ? ELs ; // Error, else non spelled right

The ground you do non acquire “ else expected ” is that you need non compose an else option so this merely looks like a bad statement.

Eclipse:

ELs can non be resolved

Syntax mistake, insert “ AssignmentOperator Expression ” to finish Expression

The same identifier can be used in different methods and categories. An of import undertaking of the compiler is to decide the ambiguity of multiple utilizations of the same identifer ; for illustration, if a variable is declared both straight within a category and besides within a method, the usage of its unqualified name is resolved in favour of the local variable. This mistake message merely means that the compiler could non obtain an ( unambiguous ) significance for the identifier ELs.

The undermentioned codification:

if ( I & gt ; J )

soap = I ;

ELs // Error, else non spelled right

soap = J ;

consequences in a eldritch mistake message:

x.java:6: can non happen symbol

symbol: category ELs

location: category ten

ELs

The ground is that the compiler interprets this as a declaration:

ELs max = J ;

and ca n’t happen a category els as the type of the variable soap.

Eclipse: Duplicate local variable maxels can non be resolved to a type These messages are more helpful: foremost, the usage of the word type alternatively of category is more exact because the type of a variable demand non be a category ( it could be a crude type or interface ) ; 2nd, the message about the extra variable gives an excess hint as to the beginning of the mistake.

The mistake can besides be caused by trying to declare a variable whose name is that of a reserved keyword:

nothingness degree Fahrenheit ( ) {

int default = 10 ;

}

Eclipse: Syntax mistake on nominal “ default ” , invalid VariableDeclaratorId

Can non happen symbol

This is likely the most common compile-time mistake. All identifiers in Java must be declared before being used and an incompatibility between the declaration of an identifier and its usage will give rise to this mistake. Carefully look into the spelling of the identifier. It is easy to do a error by utilizing a lower-case missive alternatively of an upper instance one, or to confound the missive O with the numerical 0 and the missive cubic decimeter with the numerical 1.

Other beginnings of this mistake are: naming a builder with an wrong parametric quantity signature, and utilizing an identifier outside its range, for illustration, utilizing an identifier declared in a for-loop outside the cringle:

int [ ] a = { 1, 2, 3 } ;

int amount = 0 ;

for ( int I = 0 ; I & lt ; a.length ; i++ )

amount = amount + a [ I ] ;

System.out.println ( “ Last = “ + I ) ; // Error, i non in range

Eclipse: … can non be resolved

… is already defined in…

An identifier can merely be declared one time in the same range:

int amount = 0 ;

double sum = 0.0 ; // Error, amount already defined

Eclipse: Duplicate local variable amount

array required but… found

This mistake is caused by trying to index a variable which is non an array.

int soap ( int I, int J ) {

if ( I & gt ; J ) return I ;

else return J [ I ] ; // Error, J is non an array

}

Eclipse: The type of the look must be an array type but it resolved to int

Semantic mistake

In scheduling, creative activity incorrect topographic points of cryptography, composing a valid scheduling construction with unacceptable logic. The compiler will bring forth instructions that the computing machine will put to death, because it understands the sentence structure of the scheduling statements, but the production will non be right.

Eg: –

Changing the event.

Figure1.2

Example Program in Microsoft Visual C++ Syntax Errors and Warnings Window