chapter-1 introduction introduction -...

Chapter-1 Introduction Page No. 1

INTRODUCTION

This is first chapter of the thesis, containing overview for the work done, statement of

problem, basic definition of terms and motivation for the research followed by talk a brief

discussion of all containing chapters given as the outline of entire thesis and contribution

of this research.

1.1 Overview

The programming languages have great deal of responsibility to solve the problems of

respondents. All aspect which are belong to computer field, are directly or indirectly

related to programming languages. The object oriented programming language is one of

the strong language among different languages. The Object-Oriented Design being

Applications development has been the essential reference to object-oriented technology

for long time, which has evolved to attempt the mainstream of strength of industry for a

software development. In this century, it is so challenging to develop an interactive and

efficient user interface.

The user interface (UI), in the industrial design area of machine interaction with human,

is the intermediate between humans and machines. The main goal of interaction between

a machine and a human at the user interface is control of the machine and effective

operation, the response from the machine which aids the operator in making operational

decisions. Examples of different concept of user interfaces (UI) are following.

• System Software(Operating System)

o Operating System facilitates interaction with Operator and other all the

computer resources like a government. There are so many operating

systems in market like windows, Linux Solaris etc.


• Application Software

o All the computer software which is developed to perform particular tasks

(word processing, mathematical operation, presentation, photo editing,

account management etc.) is called application software.

• Utility Software

o All the computer software which is developed to help maintain, configure,

analyze, optimize a computer is called utility software.

The main goal of human-machine interaction engineering is to design a user interface

(UI) which makes it simple, effective, enjoyable and efficient to operate a machine in the

way which produces the expected outcome. Overall the operator needs to provide

minimal input to achieve the expected output and minimizes unexpected outputs to the

operator. It is societal awareness of heavy machinery being use of the relative decline and

personal computers. The GUI has their overtone as UI. While machinery control and

industrial control design discussions more commonly refer to human-machine interfaces.

1.1.1 Hierarchy of programming paradigms

The process of problem-solving using a computer is an intricate process requiring much

thought, careful planning, logical precision, persistence and attention to detail. On the

other hand, it can be challenging, exciting and satisfying with considerable scope for

personal creativity and expression. If problem-solving is approach in the latter spirit, the

chances of success are greatly amplified.

A programmer’s primary task is to write software to solve a problem. Many

programming models have evolved to help programmers in being more effective. These

are discussed below.

1.1.1.1 Aspect-oriented programming (AOP)

Aspect oriented programming (AOP) basically design for raising modularity to allow

cross cutting technique.


AOP paradigm is concern breaking down a program into different parts. Mostly all the

programming paradigm support some level of grouping like abstraction, encapsulation of

concern into distinct and independent entities. Some other concern the encapsulation

called crosscutting; means “cut across” multiple abstractions in a code of program.

AOP implementations have expressions that encapsulate each and every concern in one

place. This implementations lies difference between usability, safety, and power of the

constructs provided. [1]

Figure 1.1: Aspect Oriented Programming execution methods

1.1.1.2.Subject-Oriented programming(SOP)

SOP allow the method of programming that supports to develop object oriented systems

as inheriting systems by composing them with new subjects, integrating systems by

composing them with one another and as compositions of subjects.

SOP involves dividing a system into writing rules to compose them correctly and

subjects. Subject Oriented Programming attempts to solve problems the cognitive

abilities of programmers by instantiate subjects.


SOP is complements OOP, solving a number of problems that arise when object oriented

programming is used to develop integrated applications or suites of inter operating or

large systems. Subject Oriented Programming paradigm relied on a compositor, that’s

why, it is reliance on class. [2]

Figure 1.2: Subject Oriented Programming Paradigm [3]

1.1.1.3.Functional Programming(FP)

Functional Programming paradigm supports computer processing as the evolution of

arithmetic functions and avoids mutable data and their state. It concentrates on functions

rather than emphasizes change in state like imperative programming.

Microsoft has also turned their attention towards FP with introduction of a.NET based

functional programming language and F#, in 2005.

FP is purely functional. Functional Programming languages have mostly been

emphasized in academia rather than in commercial software development. Functional

Programming used in commercial applications include (Haskell, Erlang, Ocaml,

Mathematica, XSLT and financial analysis) and industry.

So many non-functional programming languages like C, C++ and C# can be made to

exhibit functional behaviors using lambda functions and function pointers.

The functional programming language based on the lambda calculus. Latest version of

functional programming languages can be viewed as the lambda calculus.


Functional Programming in non-functional languages

Non-functional programming languages have features which are borrowed such as list

comprehensions from FPL and higher-order functions. Because of using all these

language it is easy to adopt a functional style.

There is possibility to employ a functional style of programming in languages that are not

traditionally considered functional languages. FP constructs higher order functions and

lists can be contained in C++. In case of C it can implement function pointers to achieve

effects of higher order functions.

Example: it can use common function design using function pointers. In version 3.0 and

higher of C#, to write programs in a functional style the lambda functions can be

employed.[4]

Figure 1.3: Functional Programming Method [5]

1.1.1.4. Logic Programming (LP)

Logic programming is used in arithmetic logic for computer programming. As far as

logic programming is concern, logic is used as a representation language of declaration.

Logic Programming adopts two methods to solving the problem; first method is that the

programmer is responsible only for assuring the reality of programs expressed in logical

form and the second method is that model generator or theorem-prove, which has

responsibility to solve the problem efficiently and effectively. Logic programming is


commonly understood. Logic can be used in procedural representation language and

declarative representation language. LP is based on the basic fact which a backwards

reasoning theorem-prove applied to declarative sentences in the form of implication:

If L1 and ………….. Ln then D

It is behave like goal-reduction procedures

For example, Logical Programming consider the implication

If the button of alarm signal will be pressed by you,

Then a possible urgency make alert to the driver of the train

As the process for the same:

The button of alarm signal should be pressed to attention the operator of the train.

Keep in mind, LDK elucidation of constructivist reason will be dependable with this; as a

result of problem D given solutions of L1……Ln there inference will be interpreted.

Conversely, logic programming’s characteristic is that group of formulas might be

considered as proof search and programs could be given a computational sense.

Restricting the underlying logic achieve to a biddable segment like traditional harrop

formulas or horn articles.

The developer will be responsible for ensuring the truth of code of programs due to the

purely declarative case. Because of infeasibility of automated proof, LP is commonly

understood, it is also relies on the developer to make certain that presumptions are

generated efficiently and effectively. It needs to be aware to achieve efficiency and

behavior of the problem solving of the theorem-prove. In this reverence, LP is equivalent

to straight IP (imperative programming). [6]


Figure 1.4: Logic Programming Architecture [7]

1.1.1.5. Imperative Programming(IP)

The IP (Imperative Programming) is other concept of programming paradigm. IP

illustrates computation in expressions of instructions that may transform a program state.

The imperative program expresses commands to take action and describe progressions of

commands for performance of computer. As far as declarative programming is concern, it

is opposite, without prescribing how to do and what needs to do in expressions of

progressions of exploits to be taken for the same. FP (Functional Programming) and LP

(Logical Programming) are examples of a more declarative method. [8]


Figure 1.5: Imperative Programming Model [9]

1.1.1.6. Event Driven Programming(EDP)

Event Driven Programming means problem solving controlling will be event based. In

EDP paradigm the problem solving is determined by user actions or event (keyboard

event-key presses, mouse event-mouse clicks) or threads or sensor outputs or messages

from different code of program.

EDP architecture can be divided into two parts: the first part includes event part and the

second part is event handling.

In any programming language can support event driven programs. It is so easy to perform

the task in languages due to high level abstractions to support for the same. There are so

many Integrated Development Environments, which provide repetitive tasks and code

generation methods for event handling. [10]


Figure 1.6: Event Handling Architecture [11]

1.1.1.7. Parallel Computing Paradigm (PCP)

Parallel Computing Paradigm (PCP) supports simultaneous execution of instructions of

the program. PCP is a different form of computation, which divides large program into

smaller parts and all the parts are solves concurrently or simultaneously or parallel. PCP

has different forms which show in following:

Parallel Computing Paradigm

Data Parallelism Bit Level Parallelism Task Parallelism Instruction Level Parallelism


Parallel computers may be considered as a supportive for that hardware which belongs to

multi-processor, multi-core systems having more than one processing elements inside a

one machine. More than one computer systems are used by MPPs, clusters and work to

do same problem.

It is so tuff to write a code for a particular problem in PCP. Because there will be

different new classes to handle concurrent execution of the programs. There is great deal

of problem between harmonization and announcement to get good performance for

parallel program. According to Amdahl’s law the result of parallelization can be achieved

so fast by speed-up of a program.

PCP basically used in high performance computing for last many years. As far as the

concept of averting frequency scaling of physical restraints, the PCP is the very ones for

the same. Due to this peculiarity, PCP has been best paradigm for last years. Now PCP is

most the dominant paradigm among other paradigms especially for multi-core processors

in computer architecture.

PCP could be separated into two models.

• The first model is called the node only model where more than one thread of a

single source code executes.

• The second model is called the host-node (master-slave) where a distinct program

(control) defined the host have responsibility to execute for different processes

collection, initialization, show outputs , timing of functions and spawning [12]

Figure 1.7: Parallel Computing Processes [13]


1.1.1.8 Recursive Programming(RP)

Recursive Programming requires divided complicated cases into the some base case. The

problem should be reduced in each recursive call. The recursion has been called as

generative method or structural method. Generative method or structural method

achieves the data that comes from a data structure as a list, this procedure can be called

structurally recursive otherwise it will be generatively recursive.

The new piece of data is generated using recursive algorithms from the input data. HTDP

(How To Design Programs) suggests generative recursive which includes the followings:

merge sort, quick sort, adaptive integration, gcd, Newton’s method and binary search.

[14]

Figure 1.8: Recursive Programming Paradigms [15]


1.1.1.9 Scalar Programming(SP)

At a time a single value should be operated, it was basis reason to develop scalar

programming (SP). SP applies that king of programming approaches which never go

with APP (Array Programming Paradigm). SP supports Low Level Programming (LLP)

approach that abstract the program to maintain data aggregation.[16]

Figure 1.9: Scalar Programming Paradigms [17]

1.1.1.10 Structured Programming Paradigm (SPP)

It can be said that Structured Programming Paradigm (SPP) is the sister concern of

procedure oriented programming (POP). SPP has been so popular being a reducing or

removing factor on the statement of GOTO (keyword). To construct structured programs,

there are different methodologies or techniques which are developed for the same. The

followings are common among them:

i. As far as Edsger Dijkstra’s view is concern, in SPP the concept or logic of a

statement is properly structured with limited ways. SPP supports the methods that

believe in understating every structure rather than understanding a program.


ii. According to Dijkstra, the program should be divided into sub parts with single

entry point.

iii. The process of aligning data structures in the source code of program is called

Data Structured Programming (DSP). DSP paradigm is also purposed by Edsger

Dijkstra. It supports primary structures. As far as constructing a program is

concern that applies high level structure for process of data structures.

iv. Ken Orr, Jean Dominique Warnier and Michael A. Jackson pointed three methods

for designing data structure program.

v. SPP design for structured programming but after 1969, to handle complicated or

large code of the program developed Object Oriented Programming for the same.

Structured Programming can be done in any programming language, but

procedural programming language can be preferable to use. During 1970 when

Structured Programming had been as famous as a technique, the POL applied the

some features into structured programming to enhance their performance. Pascal,

Ada, PL/I and ALGOL are most of structured programming languages.[18]

Figure 1.10: Structured Programming Paradigm [19]


1.1.1.11. Modular Programming Paradigm (MPP)

Module means the group of procedures that is related to data being manipulated. Modular

Programming Paradigm believes in designing of programs from procedures of the design

and toward the composition of data. MPP considers expanding the size of program.

Modular Programming Paradigm supports the data hiding principle. The grouping of

procedures of concern data is not supported by this principle. The techniques for

designing good procedures in a module are implemented for each procedure. The

definition of a stack is the example of module. The following problem must be solved.

i. The function push ( ) and pop ( ) in stack is used to user interface (UI).

ii. The user should insure that the demonstration of the stack must be done via

push ( ) and pop ( ).

iii. The initialization of stack must be done before their first use.

Bjarne Stroustrup’s C++ or C with class or incremented version of C make available a

technique the grouping of concern data, method into different namespaces. The UI of a

Stack module can be used as follows:

namespace Stack

{

char pop( );

void push(char);

}

void function( )

{

Stack::push(‘d’);

If(Stack::pop() !=’d’)

}


The main feature of Stack module is that the code is padding from the data demonstration

of Stack by code explaining Stack::pop() and Stack::push(). There is no require by the

user that the Stack is demonstrated using sequence of data (array) and it may be altered.

The data is one of the things that may want to hide. It is so large to the representation of

data hiding, which may be called functions or methods or procedure. [20]

Figure 1.11: Modular Programming Model

1.1.1.12. Procedure Oriented Programming (POP)

In the Procedure Oriented Programming (POP), the program to solve related problem is

separated into sub parts of the problem which is depending upon their functions. The sub

parts of the problem are also called method or functions or procedures. During the

execution of the program any method or procedure or function can be executed at any

time or point. There are two types of variable in the program, first is global variable and

second is local variable. The global variables can only be used.


Figure 1.12: Procedural Oriented Programming [22]

Think of each small solution as a task, to perform which you write a block of code called

a function. You can call one function from another. However, you must ensure that a

function used to change one part of the system does not have an undesirable effect on

another part of the system.

The software development in POP is procedural or functional or method-centric since it

looks at the procedures in a system. Such an approach is not ideally suited for developing

complex software because it concentrates on the processes of the application for which

the software is being developed. Consequently, the modules of the application software

constructed by such an approach are so tightly interwoven and interdependent that it is

difficult to separate one module from another. The reusability of software becomes

difficult as its complexity increases with processes.

Just as the employees of an organization can be grouped according to their functions and

then arranged in a hierarchy, you can simplify the software complexity of a system by

breaking the system into its component parts and arranging them in a hierarchy. Take the

Personal Computer (PC), for example. It is a moderately complex system. If we take a

closer look, we see that most PCs can be broken down into various components, which

can be broadly classified as the Central Processing Unit (CPU), the Visual Display Unit

(VDU), the keyboard and the secondary storage device. The CPU itself can be broken

down into its component parts: the Arithmetic Logic Unit (ALU), the math co-processor,


the clock, and the chip. Thus, entities as complex as the PC can be broken down to the

last logical component such that we know the individual functioning of each component.

While each component has its own logical function, the combined operation of each

component makes the PC function as a cohesive unit. When you break it down into its

component parts, and analyze the functioning of each part, you get a clearer picture.

Figure 1.13: Architecture of Computer

In other words, instead of trying to understand the working of a PC, it is easier to

determine its component objects, define their functions, and then determine how these

component objects interact with each other.


Let us see what would happen if we concentrate on how the PC works, instead of on the

components of the PC. Should one of the components of the PC (say, the clock chip) stop

functioning, we would not be able to figure out what precisely is wrong with the PC. If

we know the components and their behavior, we would be able to determine that the

clock chip is at fault and replace it with a new one. Thus, it is clear that an application has

to be broken down into small units for easy maintenance of software.

In the procedural approach, portions of the code are so interdependent that the code in

one application cannot be reused in another. Thus, it is not possible to use a module of an

airline reservation application that prints airline tickets to print railway tickets.

Another outcome of the interdependence between modules is that procedural or

structured software is inflexible to change. Since application areas are constantly

upgraded, the software designed for them must track these changes. In structured

software, a change means rewriting huge portions of the code. As a consequence of this,

software maintenance costs are very high.

Given the drawbacks of the procedural approach, it was only natural that software

engineers sought better approaches and methods for developing software. They wondered

why software could not be constructed the way as aircraft or a high-rise building is by

putting together several small components to build the whole. The component objects of

the application that interacted with each other could be used to build the software. What

was required in the building of software was object-orientation rather than process-

orientation.

In an attempt to solve the problems inherent in procedural programming, programmers

turned to the object-oriented programming model. POP supports Top-Down

programming method. In this paradigm error detection and identify the data by the

function is so difficult

1.1.1.13. Object-Oriented Programming (OOP)

An object is one of the first things that an infant learns to recognize. The multitude of

‘things’ that hover above its crib, that smile and talk to it, that pat its head and pinch its


cheeks are people. Sometime later, it learns to recognize other such things the circular

things with a dial on one wall of the house is a clock,

The longish 'things' arranged neatly on the shelves are books, and that weird contraption

resting on the table and making a noise is the stereo tape-recorder. Mind you, the infant

does not know that these things are named so, but recognizes them in much the same way

as it recognizes its mother and father.

As the infant grows older, it leads to recognize an object as not only having a definite,

distinct boundary, but also as something that has a unique identity, quite apart from the

other objects surrounding it.

The dictionary defines an object as a material thing that is capable of being presented to

the senses. For our purpose, a simple definition of an object would be a tangible entity

that exhibits some well-defined behavior. Take a tennis ball, for example:

� A tennis ball is a tangible, visible entity that has a visible boundary.

� A tennis ball has a defined purpose.

� You can direct a specific action towards a tennis ball, for example, hit it with a

racket and send it flying.

Let us not limit our definition of an object to merely something that can be seen, held and

touched, such as a tennis ball, a light bulb, an automobile, and an armchair. For the

purpose of software development, the concept of an object needs refinement. Take the

example of 'Acme Nuts and Bolts Company'. Unlike a tennis ball or a tape recorder, an

organization, you will argue, does not have a visible boundary. True, but while it does not

possess a physical boundary, it does have a conceptual boundary. Like all organizations,

it has a specific defined purpose, and one can direct a specific action towards it (just ask

the customers and shareholders). Thus, by our definition, Acme Nuts and Bolts Company'

is an object.

According to Grady Booch, a leading exponent of the object-oriented approach, an object

has the following characteristics:

� It has a state.

� It may display a behavior.

� It has a unique identity.


The state of an object is indicated by a set of attributes and the values of these attributes.

Thus, a chemical compound can be characterized by its temperature, pressure, and

density, and the values of each of these attributes.

The behavior refers to a change of these attributes over a period of time.

What is identity? Each object has a unique identity, just as each person has a unique

identity. Thus two tennis balls may be of the same color and material, have the same

weight and circumference, and display the same behavior but still have distinct identities.

Say, one ball has the factory seal number ALGPG1720 and the other ALGPG1721.

The following diagram displays the state, the behavior, and the identity for a light bulb.

Figure 1.14: State, Behavior, and Identity of Object

Look at the world around you. It is full of objects of different shapes, sizes and colors,

objects stationary and mobile, and objects that exist in this world for different purposes.

If we were to deal with this vast number and variety of objects simultaneously, we would

be at a loss. We can only do what zoologists do. Zoologists cannot do any meaningful

study of the millions of animals inhabiting the earth without organizing them in a logical

manner. Thus, they have classified animals into their kingdoms, genus, families, and

species.

Similarly, the millions of objects that we see in this world can be classified based on their

common attributes. Let us take a simple example from the animal world. The peacock,

the sparrow, and the kingfisher are all called Birds. Why? All of them share some

common characteristics. All three have properties that are common to the family of Birds.


All of them lay eggs, hatch their young ones, are covered with feathers, have hollow bone

structures, and have the ability to fly. Thus, we may say that the peacock, the sparrow and

the kingfisher all share structural and behavioral similarities and belong to the class

called Birds.

From the above example, we may define a class as 'a set of objects that share structure

and have a comma behavior'. We started by saying that the world around us is full of

objects. Making a conscious attempt to identify and classify the objects around you can

be fun. And (this is important from the point of view of software development), it can be

equally exciting to identify objects and classes in a given situation or situations. When we

are watching a play in a theater, we recognize the fact that there is a group of actors on

the stage and each actor is playing his or her own part. Similarly, in a given situation, we

can identify a group of objects that play a part. One difference here is that objects would

include both animate and inanimate objects. Thus, on the stage you would identify not

just Professor Henry Higgins, Col. Pickering and Eliza Doolittle but also identify things

like armchairs, the fireplace, and the portrait on the wall.

Object-Oriented Analysis and Design (OOAD)

Imagine an aircraft factory in which a new jetliner is being built, Picture several

competent engineers and workers with specialized tools, constructing a marvel of

technology. Can you visualize them working on pure intuition—grabbing the tools and

settling down to work immediately? Or, do you see them working according to an

elaborate design on which they have spent hours - pouring over each detail, working and

re-working the design, and finally constructing the aircraft based on the design?

For the sake of the millions of people who fly every day let us hope that the latter is true.

After all, it is comforting to know that a lot of thought has gone into first making a model

on paper and then translating that into the physical jetliner. The same holds true for

almost any item that is constructed. Fashion designer; for instance, put pen to paper

before attacking the fabric with scissors. Architects spend hours drawing up blueprints

before laying the bricks. So, why should the construction of software be any different?

According to a report published in Japan,


"The software industry still relies mainly on the informal paper-and-pencil approach in

the upstream development phases."

It is this 'paper-and-pencil' approach that is termed analysis and design. When we analyze

and design a system, we build a model of the system. The purpose of this model is to help

us understand the reality that we are trying to create. This model is simpler than the

system that is finally constructed. Not all the practical I aspects of building a system for

the real world can be reflected in the design. However, this does not undermine the

importance of design.

We need to distinguish between the stages of analysis and design. The analysis phase

considers the system as a solution to a problem in its environment or domain. Broadly

speaking, analysis is the stage in which the users and developers of the system arrive at a

common understanding of the system. After all, a software professional cannot be

expected to know the intricacies involved in air traffic scheduling. Similarly, airport

personnel are not expected to know the syntax of programming languages. In order to

build software for air traffic scheduling, both the software professionals and the airport

personnel must speak the same language in terms of the problem domain.

The work of software professionals in the design stage is comparable to the work of an

architect or a fashion designer. The designer generates a blueprint of the system that is to

be implemented. In this stage, the developers of the system document their understanding

of the system. (Analysis and design are described in more detail later in this session.)

Just as in the procedural approach, several experts propounded their theories of the

methodology for analysis and design; similarly, several methodologies for object-oriented

analysis and design (OOAD) have emerged. Each methodology prescribes the use of

certain tools for analysis and design. These tools differ across methodologies. Some

methodologies for OOAD that have gained prominence are those described by James

Odell and James Martin, Grady Booch, Yourdon and Coad, and Jacobson and Berard.

The identification of classes and attributes is no small task. When working on a real life

project, this step could take several weeks. As you proceed with OOD, you will realize

that you may need to take another look at the list of classes that you have identified, and


change it accordingly. Design is an iterative phase and there is always room for

improvement.

Basic Concepts of Object Oriented Programming

It is necessary to understand some of the concepts used extensively in object-oriented

programming. These include:

� Classes and Objects

� Encapsulation and Data Hiding

� Data abstraction

� Inheritance

� Polymorphism

� Dynamic binding

� Message passing

Figure 1.15: Object Oriented Programming Features

� CLASSES And OBJECTS

Much like Superman, the object has descended into our world, ready to fight the

evils contributing to the software crisis. Things were simpler in the old days. You

knew an object when you saw one. Now, with all this newly acquired knowledge


of objects and classes, you probably see objects even where there are none. So,

what is the acid test? How can you be certain that something is indeed an object?

Remember the ultimate test for an object:

"An object has state, exhibits some well-defined behavior, and has a unique

identity."

- Grady Booch

Consider a pay phone where you put in a coin and then dial the number that you

want to call. The pay phone exhibits a certain kind of behavior, that is, when you

drop a coin in and dial a number, it connects you to the person you want to talk to

at the other end of the line.

The order in which the operations are carried out is important. The pay phone

behaves in this manner because of the existence of a state. One state of the pay

phone is that of the coin inserted by the caller but not used, that is, when the

number has not yet been dialed.

The state and behavior together comprise the properties of an object. For example,

one property of the object pay phone could be the amount of money or the

number of coins to be inserted.

Grady Booch has defined a property as:

"An inherent or distinct characteristic, trait, quality or feature that contributes to

making an object uniquely that object."

Objects do not exist in isolation. They interact with other objects and react to

these interactions. These interactions take place through messages. Grady Booch

has defined behavior as:


“Behavior is how an object acts and reacts, in terms of its state changes and

message passing."

That explains the first part of the definition of an object—"An object has a state,

exhibits some well-defined behavior..." Now, let us examine the next part of the

definition - "and has a unique identity."

The identity of an object distinguishes it from all other objects. In the case of the

pay phone described here, its identity would be the serial number assigned to it by

the manufacturer.

Two objects may have the same behavior, may or may not have the same state but

will never have the same identity. The identity of an object never changes in its

lifetime. Several people have described techniques for identifying classes

According to one of these techniques, you first write the English description of

the problem. Then, you underline the nouns. The nouns represent candidate

classes.

Consider a small example that illustrates this. The statement in English about a

department store is as follows:

There are several counters, each manned by a single salesperson selling a specific

product. A customer approaches any counter, depending on the product he or she

wishes to purchase. The salesperson hands her or him a product and accepts

payment.

Let us apply the suggested technique to identify classes.

There are several counters, each one manned by a single salesperson selling a

specific product. A customer approaches any counter, depending on the product

he or she wishes to purchase. The salesperson hands her or him a product and

accepts payment.


So, the classes that have been identified are:

• Counter

• Salesperson

• Product

• Customer

• Payment

Note that some nouns occur more than once in the statement, but are listed only

once. Similarly, watch out for synonyms and do not include them in your list. You

have probably noticed that this technique of underlining nouns is not foolproof.

All nouns do not necessarily translate into classes.

Classes and objects are closely linked. You cannot consider one without the other.

While an object has a unique identity, a class is an abstraction of the common

properties of many objects.

Now that we have described what a class is, consider the following question:

"What is not a class?"

An object is not a class. A property of an object is not a class. Objects that do not

share a common structure or common behavior cannot be clubbed together in a

class.

If you have done the mammoth task of identifying classes and objects, let us

address the next important issue: what do you do with them? In the object-

oriented technique, classes and objects certainly do not end up in cold storage.

They are the basis of the object-oriented approach for system development.

In the object-oriented approach, besides identifying objects and classes, the

developer also has to define the structure of the class. This structure determines


how the set of objects provides the behavior needed to satisfy the requirements of

the problem domain.

Figure 1.16: Differences between Class and Object [23]

� Encapsulation and Data Hiding

The wrapping up of data and functions into a single unit (called class) is known as

encapsulation. Data encapsulation is the most striking feature of a class. The data

is not accessible 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 or information hiding.

To fully appreciate the OOP paradigm, we must view the overall coding process

as an exercise in shared and distributed responsibilities. These chapters have used

the terms client to mean a user of a class and manufacturer to mean the provider

of the class.

A client of a class expects an approximation to an abstraction. A stack, to be

useful, has to be of reasonable size. A complex number must be of reasonable

precision. A deck of cards must be shuffle-able, with random outcome in dealing


hands. The internals of how these behaviors are computed is not a direct concern

of the client. The client is concerned with cost, effectiveness, and ease of

operation, not with implementation. This is the black box principle, and it has

two components.

Black Box for the Client

• Simple to use, easy to understand, and familiar

• In a component relationship within the system

• Cheap, efficient, and powerful

Black Box for the Manufacturer

• Easy to reuse and modify; difficult to misuse and reproduce

• Profitable to produce with a large client base

• Cheap, efficient, and powerful

The manufacturer competes for clients by implementing an ADT product that is

reasonably priced and efficient. It is in the manufacturer’s interest to hide details

of an implementation. This simplifies what the manufacturer needs to explain to

the client, and it frees the manufacturer to allow internal repairs or improvements

that do not affect the client’s use. It restrains the client from dangerous or

inadvertent tampering with the product.

A data-hiding scheme that restricts access of implementation detail to

manufacturers guarantees client conformance to the ADT abstraction. The

private parts are hidden from client code, and the public parts are available. It is

possible to change the hidden representation without changing the public access

or functionality. If done properly, client code need not change when the hidden

representation is modified. The two keys to fulfilling these conditions are

inheritance and polymorphism.


Figure 1.17: Data Encapsulation in OOP’s [24]

� Data Abstraction

Abstraction refers to the act of representing essential features without including

the background details or explanations. 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 objects that are to be created. The attributes are sometimes called

data members because they hold information. The functions that operate on these

data are sometimes called methods or member functions. Since the classes use the

concept of data abstraction, they are known as Abstract Data Types (ADT).

Figure 1.18: Data Abstraction Model [25]


� Inheritance and Reuse

Inheritance enables a derived class to reuse the functionality and interface of its

base class. The advantages of reuse are enormous: faster development time, easier

maintenance, and simpler extensibility. The designer of class hierarchies captures

the generalizations and commonality that exist among related classes. The more

general operations are located in classes that appear higher in the derivation

graph. Often, the design considerations are application-specific.

Inheritance is the process by which objects of one class acquire the properties of

objects of another class. It supports the concept of hierarchical classification.

Figure 1.19: Inheritance Model [26]

Note that each sub-class defines only those features that are unique to it. Without

the use of classification, each class would have to explicitly include all of its

features.

� Polymorphism

Polymorphism is another important OOP concept. Polymorphism, a Greek term,

means the ability to take more than one form. An operation may exhibit different

behaviors in different instances. The behavior depends upon the types of data

used in the operation.


For example, consider the operation of addition. For two numbers, the operation

will generate a sum. If the operands are strings, then the operation would produce

a third string by concatenation. The process of making an operator to exhibit

different behaviors in different instances is known as operator overloading.

Figure 1.20 illustrates that a single function name can be used to handle different

number and different types of arguments. This is something similar to a particular

word having several different meanings depending on the context. Using a single

function name to perform different types of tasks is known as function

overloading.

Figure 1.20: Polymorphism and Dynamic Method Lookup in OOP’s [27]

Polymorphism plays an important role in allowing objects having different

internal structures to share the same external interface. This means that a general

class of operations may be accessed in the same manner even though specific

actions associated with each operation may differ. Polymorphism is extensively

used in implementing inheritance.


� Dynamic Binding

Binding refers to the linking of a procedure call to the code to be executed in

response to the call. Dynamic binding (also known as late binding) means that the

code associated with a given procedure call is not known until the time of the call

at run-time. It is associated with polymorphism and inheritance. A function call

associated with a polymorphic reference depends on the dynamic type of that

reference.

Consider the procedure "draw" in Fig. 1.20 By inheritance; every object will have

this procedure. Its algorithm is, however, unique to each object and so the draw

procedure will be redefined in each class that defines the object. At run-time, the

code matching the object under current reference will be called.

� Message Passing

An object-oriented program consists of a set of objects that communicate with each other.

The process of programming in an object-oriented language, therefore, involves the following basic steps:

1. Creating classes that define objects and their behavior,

2. Creating objects from class definitions, and

3. Establishing communication among objects.

Objects communicate with one another by sending and receiving information

much the same way as people pass messages to one another. The concept of

message passing makes it easier to talk about building systems that directly model

or simulate their real-world counterparts.

A message for an object is a request for execution of a procedure, and therefore

will invoke a function (procedure) in the receiving object that generates the

desired result. Message passing involves specifying the name of the object, the

name of the function (message) and the information to be sent. - Example:


Figure 1.21: Message Passing In OOP’s [28]

Advantages of Object-Orientation

Why do we opt for the object-oriented approach? The principal reasons are:

� Realistic Modeling.

� Reusability.

� Resilience to change.

Realistic Modeling

Since we live in a world of objects, it logically follows that the object-oriented approach

models the real world more accurately than the conventional, procedural approach.

Reusability

In the software industry, as in other industries, a large portion of time and energy is being

spent in recreating the proverbial wheel. In the object-oriented approach, you build

classes, which can then be used by several applications. The benefit of reusability

translates to a saving in time and effort, which in turn results in cost benefits.


Resilience to change

Through the object-oriented approach, systems can be allowed to evolve. When a change

is suggested, the old system need not be completely abandoned and rebuilt from scratch.

Consider the example of Joy toys, a company that manufactures toys for children in the

age group of 1 to 12. The payroll system of this company has been developed using

object-oriented techniques. The company has several employees, some of whom work in

the Design department. These designers develop new toys every season. For the past

couple of years, the company has had no cause for complaint about the payroll system.

In order to keep up with the competition, the company realized the need to employ more

designers. Design work is done only in certain months of the year. Therefore, the

company has recently employed freelance product designers who work in the capacity of

temporary employees. The original payroll system was designed for employees of two

kinds confirmed employees and trainees. Though there are many attributes that are

common to confirmed employees and trainees, like the name and the address, some

attributes are different. For example, a confirmed employee receives basic pay while a

trainee receives a stipend. The company now wants the payroll system to be modified to

accommodate freelancers as well. In the object-oriented system, this change does not

mean that the entire payroll system needs to be revamped. A new subclass called

Freelancer needs to be introduced (refer to figure) to take care of all the activities related

to freelancers. The rest of the system remains unchanged.

Resilience to change results in ease of maintenance, for the same reason, even during

construction, parts of the system under development can be refined without any major

change to other parts.

Figure 1.22: Resilience to change

Employee Employee

Confirmed Trainee Confirmed Trainee Freelaneer


Let us go through this using another analogy. What do you think of when you hear the

word 'chair'? You probably imagine something made of wood, having four legs that

support it, a seat to sit on, a backrest to allow a person to lean back, and maybe, arm rests.

Except for the arm rests, you would expect a chair to have all these attributes - you would

not expect to see a chair without a seat! This conceptual model of a chair is a class. Using

the conceptual model, you can now make a chair on your own if you were so inclined if

you did, the resulting chair would be an object. We define an object as 'an instance of a

class. Therefore the difference between a class and an object in our analogy is that a class

is the chair you imagined, and an object is the chair you made.

How would inheritance apply? Assume that after having made a chair, you want a chair

with wheels. To create a chair with wheels, you need to know what a wheelchair looks

like and what it should be capable of doing (rolling on wheels!). In other words, you need

to define a class called wheelchair. When you do this, you will find that all the attributes

and behaviors of a chair are contained in a chair with wheels. In other words, it is a 'kind

of chair. This means that it would also have attributes and behaviors of its own a unique

attribute of a wheelchair is that it has wheels, and a unique behavior is that it can roll.

How would this help in real life? You could take the chair you made earlier, add wheels

to it, and have a chair with wheels. You would not need to build the chair from scratch

and then add wheels to it. What about encapsulation and abstraction? A well-made chair

would show no evidence of the glue or nails that have been used to hold it together. All

you would see would be four legs, a seat, and a backrest. [29]

1.1.1.14. Component-Based Model (CBM)

A component is reusable software that can be easily plugged in or unplugged from an

application. It uses the basics of object-oriented programming. In a component-based

system, components interact with each other by calling methods and passing data.

So how is the component-based model different from object-oriented programming? The

component-based model is a software architecture that allows applications and systems to

be built from components supplied by different software vendors. It is a set of standards

that allows any software to communicate with other software regardless of the hardware,


the operating system and the programming language used for development. It ensures

that there is a standard method of interaction between the components. All objects need

to follow these standards when providing functionality.

The model is a specification, which defines how components can communicate with each

other. Component objects can be implemented in a number of programming languages.

[29]

Figure 1.23: Component-Based Model [30]

As shown in figure 1.23, media components are encapsulating in this model at lowest

level. This level contains images, text, video, sound, small web component and structured

text. As HTML pages may be controlled media components by inheritance with them.

The second level of this model is Content Unit Component. This level has component

that can have image with textual explanation and image with audio explanation. The

main feature of this level is reusability of component.

The last level of this model supports the introduction or overview of related chapter. This

level have documents component which is used for E-learning Course like defining

chapters and their overview, introduction, fact and example. This level is also expressed

on the hyperlink view that allowed XPointer, Xlink and XPath.[30]


Component Based Engineering (CBE) is common to all engineering concern. The

accurate system design techniques require CBE. [31]

1.1.2 Inheritance

Inheritance is the concept of reusability of source code. It is the main feature of OOP. It

is the method to create sub class or derived class or child class from super class or parent

class or base class. The sub class can have all the property and method of super class. It is

shown in figure 1.24.

Figure 1.24: Demonstration of Inheritance [26]

In figure 1.24, the direction of the arrow is opposite of your expectation. It would be label

as inheritance when it is pointed down. The direction of arrow from the sub class to the

super class is the common method. It can be though as “derived from” arrow.

The concept of reusing code relies save money, time and reliability of the program.

Inheritance is tool of distributing class libraries among different classes. It is the basic

need of OOP. [26]


1.1.2.1 Inheritance and Accessibility

As far as C++ is concern, there are three access specifies, which are named public, protected and private. The table 1.1 shows following aspects:

� There is no need to count scope of public, because the public member is allowed to access by any method at anywhere.

� On the other side, the protected data or member could be accessed by member functions of their own class and member function of derived class.

� The private data member’s scope is only inside its own class and could not be accessed from member function of other class. The scope of access specifies are shown in figure 1.25.

Access Specifies

Accessible from Own Class

Accessible from Derived Class

Accessible from

Objects Outside Class

public Yes Yes Yes

protected Yes Yes No

private Yes No No

Table 1.1: Inheritance and Accessibility

Figure 1.25: Access Specifies with inheritance [26]


1.1.2.2 Types of Inheritance

The inheritance can support following types of inheritance

� Single Inheritance

It supports that only one super class or base class or parent class can inherit into

one sub class or derived class or child class. It has one to one communication.

Single inheritance shown in figure 1.26

Figure 1.26: Single Inheritance

� Multi Level Inheritance

In this inheritance, a first class inherits into second class and the second class

inherits into third class. It has more than one level of single inheritance so it called

multilevel inheritance. It is shown in figure 1.27.

First Class

Second Class

Third Class

A

B

C

Figure 1.27: Multilevel Inheritance


� Multiple Inheritance

In this inheritance, more than one super class can be inherited into a sub class.

It is demonstrated in figure 1.28.

First C lass Seco nd Class

Third Class

A B

C

Figure 1.28: Multiple Inheritances

� Hierarchical Inheritance

In hierarchical Inheritance a single super class inherits into different sub classes.

It is shown in figure 1.29.

First Class

First Class Second Class Third Class

A

B C D

Figure 1.29: Hierarchical inheritance

� Hybrid inheritance

The Mixture of more than one type of inheritance is called Hybrid inheritance.

One can be single inheritance and second can be multiple inheritances. It is shown

in figure 1.30. [31]


Figure 1.30: Hybrid Inheritance

1.1.2.3 Window Form Inheritance in GUI

Window form inheritance is the great feature of window programming.

� Window Based Application

Before Window there was only “Command Line Interface” (CLI) that was based

on a text processing. At a time one line could be read in CLI. It is so difficult to

handle by the user. To overcome this problem, Microsoft Windows and

Macintosh operating systems was introduced during late 1980s, which was

windows-based operating system. Microsoft is concern, the windows is a 16-bit

graphical layer for MS-DOS. This provides GUI for the user.

The advantages of Windows-Based operating system and Window-base

program:

� Single or Multiple applications can be run.

� Verifying input and output resources of CPU.

� Supporting multiple colors with graphics.


� Windows Programming

Windows programming concerns with windows environment (IDE), which is

based on windows operating system (GUI). It provides window, button and events

(keyboard click, mouse click) to solve the problem. There are three aspects that

belonging to window programming, first is Window Application Programming

Interface (API), second is Microsoft Fundamental Classes (MFC) and third one is

window form.

Figure 1.31: illustrations the interaction of programs and the operating system [33]

� Features of Window-Based Programming

� Windows Form, frame, applet, message and dialog boxes are containers

for representing different problems. It supports menu layout for design UI.

� Event Driven Programming is the main feature of windows-based

program. EDP is based on responding to user on clicking a button and

moving mouse on objects and pressing key events to realize tasks.

� There are so many objects or components or tools to develop the UI

including label, push button, combo boxes, image boxes, picture boxes

and list boxes for demonstrating data or information.


� Some of components as common dialog control, files, timer, printer etc.

are controlled by the system software (OS) and provide common resources

for program.

� Operational stability is the main aspect of window applications:

� Menu bar sequences at the top of window.

� Events of components are comparable, like pressing, moving, double-

clicking, clicking, dropping and dragging.

� Saving information and managing out resource (printer) by sharing

interfaces.

� Windows-Based Programming Tools

Windows-Based Programming Tools are followings:

Example: VB (Visual Basic), VC++, BC++, UNIX C & C++ tools, java, Delphi

and Power Builder etc. Windows-based programming tools are ease of

development v/s program execution efficiency. It could be used to develop

programs easier than others (e.g. Visual Basic). The web based application can be

built using VBScript and JavaScript. But it has strong peculiarities, the tools are

built to defend web based program.[33]

Figure 1.32: Elements of a window [34]


� Form Inheritance

We have been understood that the inheritance is main feature of OOP. Inheritance

considers extending object’s properties and methods one to another, inheritance

saves the timing of developer and reduce the line of source code of related

program. Visual Basic.Net provides the facility to inherit window form and

classes. The window form inheritance is great feature of VB.net. Windows form

inheritance can be understood by following example. For instance, I want to place

the logo of Government Engineering College Bikaner at the top-left corner of

each window form of my UI and other component in the top-right corner of each

window form.

� In VB6.0 or earlier version of it, the window form could be built by

creating a template from it, or I can write source code that puts the logo

and component on each form. This process takes little bit time and it is so

tedious work. The form inheritance can also be done showing one window

form into another form.

� In VB.Net, I need to build the window form once; this form can be

inherited into application with their code and interface. If any case, the

changes are made into the master window form, all those changes will be

reflected into project or application. Windows forms are the easiest

implementation of form inheritance. The process in VB.Net is simple

rather than VB6.0.

1.1.3 Polymorphism

The polymorphism is a Greek word, which can be split into two words.

Polymorphism=poly + morphs

� Poly means more than one.

� Morphs means forms.


It means the set of instruction can be called multiple times. The polymorphism is the

main feature of OOP. If OOP does not have this feature then OOP is incomplete. There

are two types of polymorphism which shown in figure 1.33. [35]

Figure 1.33: Polymorphism Hierarchy

1.1.3.1. Compile Time Polymorphism

Compile Time Polymorphism is categorized into two aspects function or method

overloading and operator overloading. Compile Time Polymorphism can be termed as

static binding or early binding.

� Function Overloading or Method Overloading

The multiple functions, which have same name, same return type and different

arguments or parameter in a program is called function overloading. It will be

determine at compile time, which function will be called. The function

overloading or method overloading is shown figure 1.34.

Static Binding Dynamic Binding


Figure 1.34: Functions Overloading or Method Overloading [36]

� Operator Overloading

Operator overloading is the coolest feature of OOP. If the programmer has great

knowledge of method overloading and operator overloading then he can develop

their own language. Operator means, the special symbol that produce result after

process on related operands. Using this method we can assign extra feature to an

operator, which have never been of related operator. According the number of

operator which are going to operating by related operator, there are three types of

operator in OOP.

� Unary operator:- it works on only one operands.

Example: ++,--,-

� Binary Operator:- it works on two operands.

Example: +,-,*,/,%,>,<,>=,<=,==,!= etc.

� Ternary Operator: - it works on three operands.

Example: Scope resolution operator (::)

Some of operators are overload able and some of them not overload able.

There are so many languages, which are based on OOP. Some Object Oriented

Programming languages do not support operator overloading, which are listed in

table 1.2.


Table 1.2: List of Languages over-loadable and not over-loadable [37]

1.1.3.2. Run Time Polymorphism

Run Time Polymorphism is the concept of calling related code on run time. Run Time

Polymorphism can be termed as dynamic binding or late binding. The common example

of run time polymorphism is function overloading or method overloading. The

implementation of run time polymorphism into related language is several in several

languages. Let’s try to understand run time polymorphism with different languages


� In C++, sub class can be pointed from the instance or object of super class

at run time. It can be possible to achieve run time polymorphism using

pointer object of base class or super class. Run time polymorphism is

supported by virtual keyword. It can be termed as dynamic binding or late

binding. The redefinition of the function or method from super class to sub

class is calling function overriding or method overriding. In this method,

the function in super class should be defines as a virtual function. The

virtual function of the super class is abstracted to override into sub class.

The pointer of super class can point the instance or object of sub class.

This can access function or method, which are belong to super and sub

class. The sub class function can be invoked by super class pointer object

or instance being the method as virtual method. Figures 1.35 demonstrates

how to support rum time polymorphism. In this figure, the super class is

names as Base which has two virtual function named show and display.

The sub class is name as Derived which overrides virtual function show

and display. The void main has the pointer of Base class named as bptr

that points object or instance of Derived class. After than call the function

show and display using pointer object or instance of Base class via (->)

operator. Which function going to be calling, it will determine at run time

by the compiler. In this process the function of Base class will be called.

Because the both classes have same named function, which have same

return type, name and parameter. This is also called function or method

overriding. It is differ from function overloading or method overloading

with respect of parameter or arguments of function. [38]


Figure 1.35: How to support run time polymorphism

� In Java, run time polymorphism can be achieved using abstract keyword.

For example, we have a base class with different method, which is going

to extend into derived class. If the methods of base class is abstract

method that will be abstracted to override into derived class. The static

methods cannot be overridden. Java has some API named interface, which

is used to implement the user interface. Interface is not able to extents into

sub class. It can only be implemented into sub class. Interface has

instruction to declaration of related methods. All the methods, which


belong to a particular interface, are abstract methods by default. Method

overriding shown in figure 1.36 in java.

Figure 1.36: Method Overriding in Java [39]

The static methods or static variables, which are respectively called class

methods or class variable that can be accessed using class’s name. There is

no need to instantiate of class to access static methods of static variables.

[39]

� In VB6, the run time polymorphism can be implemented using runtime

files or visual basic run DLL group (runtime library). After finding out the

run time error, you should run the program then a error message will be

shown which have message prompt ‘required .DLL’ not found. The run

time errors have a lot of regions being occurred and display a message

DLL file cannot be found named as msvbm60.bll. As far as different

versions are concern VB have six versions, which have their own runtime

library. There are different service pack in VB, the latest SP6 lunched

2004. Till date SP1 to SP6 has been released, which have oleaut32.dll,

olepro32.dll and msvbm60.dll. It is required to download and after run

that. It is automatically copied into related place.[40]


Figure 1.37: Run Time Errors in VB [41]

1.1.4. Array

The group of related data, which are sequentially or adjacently arranged is called array.

Or

The group of same kind of data is called array.

Or

The concept of colonization of variable is called array.

Or

The systematic arrangement of entity or objects or instance is called array. [42]

1.1.4.1. Array Data Structure (ADS)

The array is a form of data structure, which has a collection of variables or data or

elements. Each element identified by key or index. The stored values is computed

according their index.[43][44][45] figure 1.38 shows that how to managed array data

structure in memory.

Figure 1.38: Array Data Structure [46]


1.1.4.2. Array Data Type

In which array which values will be stored, it will be determined by their data types. So

an array type can be pronounced as a data type. It describes a collection or group of

variables or values or elements. In a program all the values of an array identifies by their

index or key at run time. The collection is also called array, array value or array variable.

[47] How the base type (Integer array variable) and reference type (customer array

variable) differ from each other shows in figure 1.39.

Figure 1.39: Array Data Type [48]

1.1.4.3. Associative Array (AA)

The associative array can be referred as associative map or dictionary. It is an abstract

data type, which is collection of value or key pairs. The unique key determines the

position of value in collection. This data type allows the addition, removal, modification

of pairs and lookup values associated with related key. [49][50] How are the keys

associated with values? It is shown in figure 1.40.


Figure 1.40: Associative Array [51]

1.1.4.4. Bit Array (BA)

The bit array is a form of data structure. It is also called as bit vector, bit-set or bitmap.

The bit array stores bits in very compact form. It is used to implement bit level

parallelism in hardware. Basically it stores kw bits, where w stands for the no. of bits in

the particular unit of storage and k stands for nonnegative integer. [52] Figure 1.41 shows

that the Bit Array contains the actual array of bits and the methods to set and reset

individual bits. The Bit Array Cursor (BAcursor) is a transient itterator used to scan a Bit

Array. A single Bit Array can have multiple associated BAcursors.

Figure 1.41: Bit Array Representation [53]


1.1.4.5. Dynamic Array (DA)

Due to some peculiarity of dynamic array, it is also named as array list, growable array,

dynamic table, mutable array or resizable array. The elements can be added or removed

in dynamic array. Dynamically Allocated Array (DAA) and Dynamic Array (DA) are not

same. DAA’s size is fixed during the memory allocation of array; Whereas DA may be

fixed size. [54] Figure 1.42 simply represent that how the dynamic array allocation at run

time.

Figure 1.42: Dynamic Array [55]

1.1.4.6. Parallel Array (PA)

The parallel array is example of two dimension array. PA represents array of records. PA

consist same type of array for each column, which have same no. of elements. It also can

be called matrix or relation or table, which means group of row and column. Each

column has type of record. PA is so simple to understand. It is used to declare column

with record. [56] Parallel array demonstration shown in figure 1.43 that two single

dimension parallel arrays each holding five elements one of integer data types and one of

character data types.


Figure 1.43: Parallel Arrays [57]

1.1.4.7 Sparse Array (SA)

The Sparse Array is different from other arrays. Most of the elements of a matrix have

same type values in that case it is called sparse array that values known as default value.

Usually default value does 0 or null. As far as computation and storage is concern sparse

array is inefficient in case of large size array. There are two types of sparse array; first

concern with one dimension array shown in figure 1.44 and second belongs with two

dimension array shown in figure 1.45.[58]


Figure 1.44: Sparse One Dimension Array [58]

Figure 1.45: Sparse Two Dimension Array [59]

1.1.4.8. Variable Length Array (VLA)

Variable Length Array is allocated during late binding instead of early binding. As far as

programming language is concern, there are some of them, which support VLA named as

Algol 60, Ada, APL etc. and some of them don’t support for the same named as C#,

COBOL etc.[60] Figure 1.46 shows how to Variable Length Array is managed in

memory during late binding.


Figure 1.46: Variable Length Array [61]

1.1.4.9. Jagged Array (JA)

Jagged Array is also known as life Vector. Instead of one dimensional array and two

dimensional array, the Jagged Arrays are n-dimensional array where n is greater than

two. In JA each row has various length whereas two dimensional arrays are rectangular

means all the rows have same length (column). Infect JA is arrays of arrays. Let’s try to

understand for the same. For example, we declare a jagged array named JA.

int [ ][ ] JA=new int[3][ ];

JA[0]=new int[3];

JA[1]=new int[5];

JA[2]=new int[2];

At the time of declaration in C# need two sets of square bracket, first bracket determine

rows of jagged array and second bracket determine column of each row.[62] Figure 1.47

shows the logical structure of jagged array. First row has three columns, second row has

five columns and third row has two columns.

Figure 1.47: Jagged Array [62]


1.1.4.10. Array Processor (AP)

Array Processor means a central processing unit. AP is also known as a vector processor

that execute group of instruction which operate on 1D array’s data can be called vectors.

It is used to improve performance of numerical simulation, workloads and other tasks.

AP introduced on 1970 and considered in super computer design. In video game console

hardware are controlled by this technology. AP executes a single instruction in multiple

data (SIMD) in the same clock cycle. It is also support Multiple Instruction Multiple Data

(MIMD). [63] Figure 1.48 demonstrates how to process a Single Instruction issued using

array processor ALU1, ALU2, ALU3 and ALU4.

Figure 1.48: Array Processor [64]

1.1.4.11. Array Programming

The main purpose of array programming is that the task execute only one time to an

entire set of values. It is high level model. It provides the freedom to programmer to

realize and operate on data. [65] Figure 1.49 shows the reserved space of the array before

initializing and storing values after initialization.


Figure 1.49: Array Programming [66]

1.1.4.12. Array Slicing (AS)

The process of extracting particular elements from an array to another array with distinct

index ranges and dimensions is called array slicing. The process of extracting substring

from a string (e.g. “ven” from “deven’) and a column of a matrix, that is called vector.

The range for substring may be determined at late binding. It may be explicitly

mentioned on early binding. It is also help to matrix transpose. There is no effect on the

real array due to array slicing. The new or latest array has elements being copied from

real array. [67] Figure 1.50 shows different slices of two dimension arrays with distinct

block with different colors.


Figure 1.50: Array slicing in 2D array [68]

1.1.4.13. Global Array (GA)

Global Array (GA) considers as a library, which is innovated by scientists at Pacific

Northwest National Laboratory (PNNL) for parallel computing. Some API provided by

global array for shared memory programming and distributed memory programming for

M-Dimensional array. The global array API provides global address space (GAS)

programming languages, which is developed to realize or achieve high performance

computing. [69]

1.1.4.14. Control Array (CA)

The array of control or component or tool or object is called control array, which share

same name and event procedure. The CA will have minimum resources at design time.

To construct a control array, we should assign the same type (textbox, label, button,

option button etc.) and name with different index property of each component. The value

of index property of control must be non negative. Each control of a control array can

have different property such as color, font size, visibility etc.


� Control Array in VB

The time of the form designing, it can be created. The CA can be created using

following methods:

� First method

� Drag a control or component from toolbox to drop on the form and

set the index property with non-negative numeric value. After the

process control array will be created with one element.

� Second Method

� Design your form with two same controls (textbox or label) and

assign same name for both of them. There will be warning dialog

box displayed, which have message prompt (“this name has been

already assigned for other control”) and asks would you like to

create a CA. then click on yes command button among them.

� Third Method

� After designing your UI select any control or component and copy

using CTRL+C or edit->copy then paste using CTRL+V or

edit->paste. There will be warning dialog box displayed, which

have message prompt (“this name has been already assigned for

other control”) and asks would you like to create a CA. then click

on yes command button among them. The controls will have same

name with different index.

CAs greatest feature of Visual basic IDE, which provide a lot of flexibility for

programmer to their programs:

• All the controls which belong to a CA will have same event procedure. It is

method to reducing the code for a developing an application.

• During late binding we can add new control to a CA. it means CA can be created

at run time which not available at design time.


• CA’s elements contain limited resources than a simple component. VB provides

256 different control’s name. CA can overcome this limitation for the same.

• Dynamic creation of CA is most important feature of VB. It has been helpful to

increase capability of application.

• As far as dimension of an array is concern; the CA can only be one dimensional.

So it has no need to have dimension. It is expandable means after adding any

control for further requirement to control array, the control array will be

automatically extended. The position can be traversed of related element or

control of control array using their index property’s value. The index of first

element of control array is 0.

Figure 1.51: Control Array of Textbox at design time

� Sharing Event Procedures

All the elements of CA shares event procedure at standard module. The

event procedure of element can be recognized easily being having extra parameter

named index. The parameter index gets the value of element’s index that called

the event procedure. This is shown in this example:


All the elements of CA share the same event procedure at standard module. Each

element (Textbox) can have individual back color or fore color. For example, one

textbox get yellow back color at time being got focus and after lost focus that can

have white color.

� Dynamic Control Array (DCA)

Dynamic Control Array (DCA) loads at run time. For example, design a form to

create a control array on a particular event. It requires control data type to create

dynamic control and set the property to add control. The method to create

dynamic control array shown in following example:


� Iterating and Creating Control Array

Iteration means single statement is executed repetitively. It can be done using

looping structure. The looping can be used for creating and iterating control array.

There are some looping structures are available like for….next, while…..wend, do

while…..loop.

For example:


1.1.5. Sorting Algorithm

Sorting is the process that arranges data according to a required order (Ascending or

Descending). For example, if we have a list of students, that can be sorted by student’s

name, by roll no., by age. We have different sorting algorithms named bubble sort,

selection sort, insertion sort, merge sort, heap sort, quick sort and shell sort. Sorting is the

main technique in computer science. The large number of data can be arranged by

required order quickly.

The data processing belongs to sorting algorithms. Some complex sorting algorithm may

create complicacy which can be more than their worth for small list of data. But it may be

vice versa in case of large collection of data. The running time of data sorting depends

upon sorting technique. If we want to use a sorting algorithm then first of all we should

think that the larger value (or smaller) must be compare with other value. This process

should be systematic to compare value. Secondly, if during the comparison come to

found not suitable position for value then both values should be exchanged. Although it is

an expensive method but it is required to evaluate the efficiency of the sorting algorithm.

In this section, I have evaluate three sorting algorithm (bubble sort, selection sort,

insertion sort) among all of them.

� Bubble Sort (BS)

The bubble sort algorithm is simple technique, which requires more than one

passes via a list. The entire sorting algorithm works with array. In this technique,

a value compares to adjacent value and swaps the value, if it is out of order. The

data places at proper place in the list during each passing. The data “bubbles” up

towards their proper place.

Figure 1.52 shows the logical structure of BS’s first pass. The grayed elements

seem compared if they are out of bound. If the list has n-values then n-1 pairs of

value is required to be compared on the first pass. In this figure, it is clearly

shown that once the largest value (part of a pair) found in list, that value will

continuously be moved their proper place until completion of pass.


Figure 1.52: First Pass of Bubble Sort [70]

After completing the first pass, the second pass starts while the largest value is

placed their proper place. The second pass is being started; the n-1 items are left

to sort. So the n-2 pairs remains to compare. After completing each pass the next

largest value will be placed on their proper place. The n-1 passes are required.

During the passes, the smallest value will be placed their correct place. After for

the same, there is no need to pass. Figure 1.53 shows a function to bubble sort,

which named as bubble Sort. There is a reference array used as parameter in this

function that contains list of item. This parameter gets the list of items during

calling the function and makes modification into list of items by comparison with

each other. [70]


Figure 1.53: Bubble Sort Algorithms [71]

During each pass, the exchange operation between two values (“swapping”)

occurs, if it is necessary. The process of swapping between two values needs

temporary variable to store related value. If we don’t use temporary variable then

one value will be overwritten. It can be understand such as

Figure 1.54: Swapping During Bubble Sort

The table 1.3 shows the list of passes with their comparisons. It demonstrate that

first pass will compare n-1 pairs, second pass compare n-2, third pass compare n-3

and n-1 pass compare 1 value.


Table 1.3: The Comparison with Each Pass in Bubble Sort [70]

� Selection Sort (SS)

This sorting algorithm is an important sorting technique. Selection Sort is

improved technique over bubble sort technique. During each pass through list, it

makes only one exchange. In this technique, the largest value is to be selected to

place on their correct location during each pass. In bubble sort technique, the

largest value places on their correct position and after second pass are to order

next largest value on proper place. To sort n items require n-1 passes. The last

largest value must be placed their correct position after completing n-1 pass.


Figure 1.55: Selection Sort Algorithm with different passes [70]

The selection sort process shows in figure 1.55. This figure clearly shows that a

largest value places their correct position during each pass. It demonstrate that the

first pass select largest value (93) places their correct position, the second pass

select next largest value (77) places proper place, the third pass select next largest

value (55) places proper place and so on. Figure 1.56 shows a function to

demonstrate selection sorting technique named selection sort. [70]


Figure 1.56: Selection Sort Algorithms [72]

� Insertion Sort (IS)

This sorting technique is the simplest algorithm. It works with O (n2) method, it

has sorted sub list of the list before completing sorting. Whatever we insert the

data into list that will be inserted back into sorted sub list. As far as algorithm’s

efficiency is concern; Insertion Sort technique is not so efficient for large amount

of list like merge sort, quick sort or heap sort. But insertion sorting algorithm is so

efficient for small list of items.

• It can be implemented very easily.

• In insertion sort algorithm, the user insert data into list, at that iteration

being occurred to iterates sorted sub list and find out related position for

inserted data into array.

• This process sustains till no input remain.

• Whenever we insert the data into list, it investigate that the value is larger

than sorted list or not. If it is larger then moves after the next and it is

smaller then it finds the proper place in sorted sub list.

In the Figure 1.57, it shows some part is grayed and other part is not grayed. The

grayed part is the sorted sub list of the list. Let’s try to understand the mechanism,

assume that we create a list which has only one item placed on first (0 position), it

can be understood as sorted, it means each passing through list, inserted item will


placed on at 1st position or shift item to 1st position from 0th position through n-1

by compare or we can say that the item insert at right side being greater then

sorted list and vice versa.

Figure 1.57: Insertion Sort Algorithms [70]

The demonstration of the vth pass of insertion sort algorithm is shown in figure

1.58. In this figure, we can easily understand the sorting process. The top of figure

represent sorted sub list containing 17, 26, 54, 77 and 93. If we insert 31 data into

list than the value will compare with 93, 77, 54, which will be shifted to right side

of sorted sub list against given value 31. After completion of the process, we will

have six items as sorted sub list.


Figure 1.58: Fifth Pass of Insertion Sort Algorithms [70]

The Figure 1.59 shows the Algorithm of insertion sort using function named as

insertion_sort. It demonstrates that how insertions sort can be implemented

programmatically. [70]

Figure 1.59: Insert Sort Algorithm [73]


1.2. Statement of Problem

Object Oriented Programming language is strong language in current vogue.

There are several features of OOP’s like object, class, data abstraction/Encapsulation,

polymorphism, inheritance and message passing.

There are also available different types of languages according to their interfaces

like Graphical User Interface (GUI) and Character User Interface (CUI).

Figure 1.60: Types of Languages

All GUI based languages are itself Integrated Development Environment (IDE)

means which have different windows to develop an interactive and efficient interface or

application like form window, code window, project explorer, toolbox, property window,

object browser, immediate window, form layout window, locals window, watch window

etc. during the development of application we require different object or control or

component like label, textbox, button, checkbox, scrollbar etc. all the components have

their properties. As far as my research is concern; I will use window based programming

language. The language name is concern, it is visual basic.

Visual basic is the strong object based IDE. It supports to develop any kind of

User Interface. Some time we require copy of control (object or component) during the

development of an interface. But in visual basic, if we trying to do for the same, then a

control array of related object will be created. This will have same name with different

index. Due to creating control array, it is so complicated to handle with code. Generally


the control array is used to develop a calculator or comparisons of different sorting

algorithm etc. other then it is not used. In fact, there is limited use of control array. Not

only, we know about the program of calculator but also there has been developed a user

interface (UI) using control array, which UI is capable to compare different sorting

algorithm and show result for the same.

After studied previous section in this chapter, I concluded that Object Oriented

Programming language is correct option to research and the features of OOP’s are

ultimate concept like polymorphism, inheritance etc. I should adopt an object based

programming language like visual basic. VB provide graphical user interface, no dough it

will take comparatively less time to develop UI and less line of code to program. In

Visual Basic, I just noted that the control array, which has their limitation, can be my

research topic.

As per data structure is concern; there are different sorting algorithms, which are

described just before of this section. The different sorting algorithms have different

methods to sort the list of data. The sorting is little bit difficult to understand by someone

and make understand to someone. The sorting is directly belonging to array.

As far as statement of problem is concern; the control array can play great role to

develop a user interface (UI), which can overcome the problem to understand different

sorting algorithm being some optimization and polymorphism, inheritance can be helpful

to increase their efficiency and effectiveness of UI. As per research is concern, an UI can

be developed, which should have different panel to demonstration to process of sorting

and their algorithm. In this UI, the first panel should have list of data in textbox (control

or object or component or tool), the second panel should demonstrate related sorting

algorithm with array of label (control or object or component or tool) and third panel

should have buttons that control the sorting process in first panel, provides tracing view

of sorting algorithm with their speed, this panel should also have control like scroll bar.

Different sorting algorithm form (child form) must be controlled at a single form (MDI

form) as per requirement of user. The all the problem can be solved using control array,

inheritance and polymorphism in Visual Basic.


1.3. Key Objectives of the thesis

We all know that an interactive User Interface (UI) have been required by user since

beginning to solve their problem. Due to this requirement all the productive entities are

busy to develop for the same. The efficient and effective UI can produce good result with

taking minimum time. So a good UI can solve great deal of problem in simple manner.

As far as academics are concern; the different sorting methods in data structure are main

issue for the student to understand. It has been hectic for the student to understand

different sorting algorithm.

The main objective of this is to develop a User Interface (UI), which will demonstrate

different sorting process, tracing sorting algorithm with controlling their speed being

some optimization into development.

There are different types of sorting methods to order data in proper manner. In this thesis,

I have targeted three sorting method to involve in UI named as bubble sort, insertion sort

and selection sort. The UI will help to understand these sorting processes and their

algorithms for respondents. The respondent can be among trainer, students, and

professionals. To develop the UI, I require a programming language to design my

purposed UI. The language visual basic will help me for the same, which have GUI based

control or object, or component or tool. As I mentioned earlier that array of control is

called control array. The control array can be created with different method, which is

mentioned earlier. The control array will play main roll to design my user interface.

Because the sorting is directly related to array then it will be basic need for the same. If I

want to design a great UI then I require other features of object oriented programming

language like polymorphism and inheritance.

So, the key objective of my thesis is to design a UI, which will be definitely helpful for

the respondent to understand sorting method, who deals with sorting data. It will also be

boon for the student, who will not need any trainer or teacher to understand sorting

algorithms that belongs to their academics. It will also be great technique to deal with


students for professionals. The key objective of thesis is demonstrated in figure 1.61.,

which will clearly show the purposed model of UI.

Figure 1.61: Purposed Model of User Interface

Parent Form or

MasterLayout Tracing View of Sorting Algorithm

Co

ntro

l pa

ne

l

So

rtin

g P

roce

ss

Speed Controller


1.4. Background

All the applications that were developed being simplify the problem of user can be

consider as the background of my research. There are a lot of examples to describe for

the same that are following.

• A bank implements software (UI) to simplify the working method for employee.

This UI is able to handle all the banking related work like account management,

loan particular etc.

• The railway uses other UI to customer for related journey like reservation,

cancellation etc.

• Air ways use software that are based on simulation and the software controls air

traffic.

• A hotel implements an UI to manage their activity properly such as check in or

check out or salary management of employee etc.

• The defense authority of the country works with approved UI that helps to defend

concern country from another country.

• In the medical field, a UI has been play great role to determine disease of patient

like ultra sound, brain scan etc.

• A lot of show rooms have software to handle purchasing, selling statement, stock

management etc.

• Social web sites are used to interconnect with whole world. It has also been the

media of entertainment for users.

• The programmer generally adopts that kind of language to develop software that

supports GUI.

There are a lot of UI, which are used in academics to solve the related problem with

animation or GUI. Overall, it seems that an interactive UI has been basic requirement of


whole world since beginning. The background of my research is all the UI that simplify

the problem.

1.5. Motivation to This Research

I have seen a lot user interface in the form of system software, application software and

utility software. I feel that the system software is basic need for computer system. It is

able to control all the peripheral, which are attached with computer system. The

application software are developed to solve a particular problem like word processing,

graph making, database management, presentation making, photo editing, account

management etc.

Basically, I was motivated due to utility application. There are a lot of utility applications

such as media players, type writer, video games, calculator, other application that are

used in academics etc. There are following region being motivated.

• An UI that is developed by Randy Birch. This UI is developed to calculate the

taken time by different sorting such as bubble sort, selection sort, shell sort and

quick sort. The UI have different push buttons to control the process. To sort the

data, he used an array containing list of dates. I was inspired to develop such type

of UI.

• I also observed about the source code of the calculator. I felt, there is control array

of button (0 to 9) and (/,+,*,-,=) that use only a single event procedure to calculate

the given number.

Both aspects have been main region behind my research. The first aspect motivated about

the appearance of UI and the second is motivated that how it can be developed using

control array.


1.6. Outline of Entire Thesis

This thesis divided into eight chapters. The first chapter is an introductory part of the

research study. This chapter gives us the transparent introduction to the research work

followed by the purpose of the research, contribution and overview of the entire thesis.

The next second chapter explores the review of the literature and theories associated

with interface, OOP, inheritance, polymorphism, array, control array, sorting algorithm

and implementation. The third chapter is describing material and methods with research

methodology containing the process of data collections and presentation. The fourth

chapter represents the observation, results and discussion from research work done. In

the fifth chapter conclusion and important finding are given with in order to accomplish

an analysis. The sixth chapter represents the recommendations of the thesis approach

and new purposed scenario with empirical findings. In seventh chapter bibliography is

given which is used in this research study. At the end of this thesis, eighth chapter is

given which describe our published paper related to this research in national and

international conferences and journals.


1.7. Contribution of This Research

The contribution of my research work will be as a tool for students, trainer or any

respondent who want to learn different sorting process and understating their algorithm

such as bubble sort, selection sort and insertion sort. The sorting of data is main part of

data structure, which is in the curriculum of students of different stream. It is also

challenging for trainer or teacher to make understand the algorithm to the student. The

implementation of my research as an UI will be helpful for the same. Academically, this

UI will play great role to simplify the sorting process and tracing related algorithm. This

UI will also provide tracing speed controller that will help to control the speed of the

sorting process and tracing algorithm. So the respondent can learn according their ability.

If he is comfort with default speed, it will do. Otherwise he can decrease or increase

process speed according to their requirement. This UI provide a demonstration that will

have ten different values to be sorted. Otherwise the respondent can say to no. of data to

be sorted. But the respondent cannot assign more than fifteen elements. I am very sure

that my research may be appreciable.

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