SE-IT JAVA LAB OOP CONCEPT

Fundamental concepts of object
oriented programming

Overview of programming
• Programming: programming language is
artificial human created language which
translates instruction from human redable
to computer readable format.
• Programming is art of solving
computational problems by.
• To solve these problems we use
programminglanguage.

Concepts of Procedure oriented
programming

Procedure Oriented Programming(POP)
• Programming languages such as like
COBOL ,FORTRAN,C (using high level
languages) were based on Procedural
Oriented Programming(POP) language.
• POP language program uses branching
statements and procedures to execute one or
other set of instructions, depending on the
result that you want.
• Procedure also known as a routine or
subroutine or a function.

Procedure-Oriented Programming
• Procedure-oriented programming basically
consists of writing a list of instructions for
the computer to follow and organizing these
instructions into groups known as functions.
• When you write large programs in Procedure
Language ,they are complex to understand
and hard to program.
Note:Procedural programming is a programming
paradigm in which a program is composed of one
or more procedures which are invoked in a
particular order to achieve the desired result. Every
procedure is a set of instructions representing a
specific task.

Note:
• In structured programming(like c) we can
overcome this problems by dividing a
Large program into different functions.
• But it gives birth to other problem.
• Structured programmingis any
programmingwhen functionality is
divided into units like for loop, while
loop, if... then etc block structure.
Also, here the a piece of code
(function) can be re-used.

Typical structure of procedure-oriented program
Function-1 Function-2 Function-3
Global data
Main function
Local data
Function-4 Function-5

Characteristics of Procedure-
Oriented Programming
• Large programs are divided into smaller
programs known as functions.
• Most of the functions share global data.
• Data move openly around the system from
function to function.
• Functions transform data from one form to
another.
• Employs top-down approach in program
design.

Relationship of data and functions in
procedural programming
Global Data Global Data
Local Data Local Data Local Data

Problem of Procedure
oriented programming?
• In procedural language main problem are
The functions have unrestricted access to
global data.
• No security for data. If we declare a variable
before main function then it can be accessed
freely from any function present in the
program.
• No better memory management.
• Difficult to implement today's client
requirements

Problem of Procedure
• No structure or code reusability. Hence time
of development, testing and length of
program increases.
• As length of application increases it causes
slow performance.
• Code maintenance and enhancements are
difficult.
• No proper way method for Exception
handling (error handling).

Some other Problem of Procedure
• Computer languages generally have built-in
data type : interger,character,float etc.
When we try to invent a new data type or a
user-define data type. Then it become very
default to create it.
• e.g. we work with dates or complex no. then it
becomes very difficult to work with built in
types .
• Crating your own data types is a feature called
of extensibility.
• Procedure oriented language are not extensible

This problem is overcome by with the
development of new programming technique
known as object oriented programming(OOP).

• POP the emphasis is on functions rather than
data, and data is also not secured in this
approach.
• The OOP approach eliminates these
weakness of POP by combining the data and
the function that work on it into a single unit
called class.
• So the data is secured from the outside world
• OOP is implemented on the real-world
entities called objects that have some
characteristics and behavior,

Contents
1. What is OOP?
2. Classes and Objects
3. Basic Concepts of OOP
Abstraction
Encapsulation
Polymorphism

What is OOP?
• Object Oriented Programming(OOP) is an
Engineering approach for building software
systems.
• Based on the concepts of classes and object
that are used for modeling the real world
entities.

What is OOP?
 Better suited for….team development.
 Facilitated utilizing and creating
reusable software components.
 Easier for GUI Programming
 Easier for Software maintenance
 All modern language are object
oriented: Java, C#, PHP, Perl,
C++,...…..

Real world object
• In physical world we deal with object like
person or car.
• Such object not like data and functions.
• In complex real world situations we have
attributes & behavior.

Attributes :
• Every object has some attribute different
types of objects contain different attributes
or characteristics.
• Example :
The student are name,rollnumber,subject
The attribute for car whould be color,
engine power,number of seates etc.
• Attribute are real world are like data they
have some specific value Raj(for name) or
23(roll number).

Behavior
• Behavior actually determines the way
an objects interacts with other objects.
• Like function to do some task.
• e.g if manager orders an employee to do
some task then he responds either by doing
it or not doingit.

OOP …Object
continue …
• In Object Oriented Programming deals
with similar objects.
• The data of anobject canbe accessed only
by the functions associated with that object.
• Functions of one object can access
the functions of another objects.

Organization of data and functions in OOP
Data
Functions
Data
Functions
Communication
Data
Functions

Basic Concepts of Object-Oriented
Programming
• Objects
• Classes
• Data Abstraction and Encapsulation
• Inheritance
• Polymorphism
• Dynamic Binding
• Message Passing

Objectsin OOP
• Object are the basic run-time entities in an
object-oriented system.
• They may represent aperson, aplace ,
abank account, a table of data or
• Objects take up space in the memory
• When aprogram is executed, the objects
interact by sending messages to one another

OBJECT
HAS DOES
color
diameter
brand
bounce
roll
properties behavior

If there are two objects customer and account
then the customer object may send a message to
account object ..requesting for the bank balance.
Object : CUSTOMER Object :ACCOUNT
Objects example
DATA
AC No.
Name of AC Holder
Address
FUNCTIONS
Deposit
Withdrawal
AC Balance Display
DATA
AC No.
AC Balance
T
ype of Account
FUNCTIONS
Account Balance

Classes
• A class is user-defined data type which contains
data members and member
functions...Members function operate those
data Members.
• Classes are user defined data types and behaves
like the built in type of aprogramming language.
• Once a class has been defined, we can create any
number of objects belonging to that class. Thus a
class is collection of objects of similar type.
• class is collection of similar kind of objects.

OBJECT
Classes :The entire set of data & code of an object can be
made a user-defined data type with the help of a class.Objects
are actually variable of the type class
HAS DOES
color
diameter
brand
bounce
roll
properties behavior

Classes
• A Class is a collection of fields (data)
and methods (procedure or
function) that operate on that data.
• Class are just like the blueprints of objects
that model real world things.
• one of advantage of using classes is that
once you have created a class for acertain
type of object you canreuse that class in
any project.

A class Is defined by 3element
1.A unique class name
2.Data members or attributes
3.Member functions or methods
circle
centre
radius
circumference()
circumference()
area()

Circle
centre
radius
circumference()
area()

OBJECT
A class describes an object
HAS DOES
color
diameter
brand
bounce
roll
properties behavior

OBJECT
a classdescribes an object
Class ball
String color;
float diameter;
String brand;
void bounce(float h)
void roll (float d)
HAS DOES
color
diameter
brand
bounce
roll
properties behavior

Circle ball
String color;
Float diameter;
Data members
String brand;
void roll (float d)
Members methods

The syntax for defining classin c++:
class class_name
{
private :
variable declarations;
functions
declarations; public:
functions declarations;
};
void main()
{
class_name variabale_name;
….
}

The syntax for defining class in java :
class class_name
{
private
functions
declarations; public
functions declarations;
}
class mainclass_name
{
public static void main(String args[])
{
class_name variabale_name=new class_name( );
….
}
}

example of class in Java
class ball
{
String color;
float diameter;
String brand;
{ }
void roll (float d)
{ }
}
class ballmain
{
public static void main (String args[ ])
{
/
/Following statement
would create an object
ball b=new ball( );
}
}

Ball b =new Ball();
b.color=“white”;
b.diam=2.0f;
b.brand=“nike”;
b.bounce();
b.boll();

OBJECT
Properties
i.e data member
Behavior
i.e method

Basic Concepts of OOP
Data Abstraction and Encapsulation
oThe wrapping up of data and functions into a
single unit is known as encapsulation.
oThe data is not accessible to the outside world,
and only those functions which are wrapped in the
class can access it.
oThese 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.

Data Abstraction & Encapsulation
oThe attributes wrapped in the classesare
called data members and the functions that
operate on these data are called methods or
member functions.
oSince the classes use the concept of data
abstraction, they are known as Abstracted
Data Types (ADT).

Data Abstraction :
The concept of abstraction isclosely related
to the concept of data or information hiding
abstraction separates qualities of data type
& the associated implementation detailed.
this helps the properties of the abstract
data types user interface while the
implementation detailed remain hidden.

Inheritance
o Inheritance is the process by which objects of
one class acquire the properties of objects of
a
c
o
n
n
o
t
i
n
t
u
h
e
e
…
rclass.
o It supports the concept of
hierarchical classification.
o Inheritance is a compile-time mechanism in Java
that allows you to extend a class (called the
baseclass or superclass) with another class
(called the derived class or subclass) or
o The mechanismof deriving a class from another
existing class is called as inheritance .
o Access specifies:- public, protected
,private, default. 

Property Inheritance
Bird
Attributes:
Feathers
Lay eggs
Flying Bird Non-flying Bird
Attributes:
------------
------------
Attributes:
------------
------------
Robin
Attributes:
------------
------------
Swallow
Attributes:
------------
------------
Penguin
Attributes:
------------
------------
Kiwi
Attributes:
------------
------------

Derived class-base class declaration syntax in Inheritance :
class A
{
……………
……………..
}
class B extends A
{
…………..
……………
}
class c extends B
{
……………
…………… }

Inheritance :
o Inheritance provides the idea of
reusability.
oWe can add additional features to an existing
class without modifying it.
(By deriving new class from existing one. The
new class will have the combined features of both
the classes.)

Polymorphism:ability to take more than one form
o An operation may exhibit different behaviors
in different instances.
o The behaviour depends upon the types of
data used in the operation.
o add( 3, 5) gives 8.
o Add(“hello”, “-world”) gives “hello-world”.

Polymorphism
o ability to take more than one form
oThe process of makingan operator to exhibit
differen
t behaviors in different instances is known as operator
overloading.
<
< Insertion Operator
<
< Left-shift bit-wise operator
oUsing asingle function name to perform different types of
tasks is known as function overloading.
add( 3, 5) gives 8
Add(“hello”, “-world”) gives “hello-world”

Dynamic Binding
o Binding refers to the linking of a procedure call
to the code to be executed in response to the
call.
o Dynamic binding (late binding ) means that the
code associatedwith agivenprocedure call is
not known until the time of the call at run-
time.It is associated with polymorphism &
inheritance.

Message Passing
• An oop consists of a set of objects that
communicate with each other.
• oop involves the following steps:
oCreating classes that define objects and theirbehaviour.
oCreating objects from class definitions.
oEstablishing communication amongobjects.
•Objects communicate with one another by
sending and receiving information.

Message Passing
o A message for an object is a request for
execution of a procedure.
o The receiving object will invoke a
function and generates results.
o Message passing involves :
oThe name of the Object.
oThe name of the Function.
oThe information to be send.

Benefits of OOP
• Inheritance – eliminate redundant code and
extend the use of existing classes.
•
• We can build programs from the standard
working module.
secure programs that can not be invade by code
in other parts of the program.
• Multiple instances of an objects can co-exists
with out any interference.

Benefits of OOP
• It is easy to partition the work in a
project based on objects.
• Object-oriented system can be easily
upgraded from small to large systems.
•
communication between objects
makes the interface descriptions with
external systems much simpler.
• Software complexity can be easily
managed.

Characteristics of Object-Oriented Programming
• Importance is on data.
• Programs are divided into objects.
• Objects may communicate with each other
through functions.
• Data structures are designed such that they
• Functions that operate on the data of an object
are tied together in the data structure.
• Data is hidden and can not be accessed
by external functions.
• New data and functions can be added easily
whenever necessary.

Difference Between Procedure Oriented Programming
(POP) & Object Oriented Programming (OOP)
Procedure Oriented
Programming
Object Oriented
Programming
Divided Into
In POP, program is divided
into small parts
called functions.
In OOP, program is divided into
parts called objects.
Importance
In POP,Importance is not
given to data but to functions
as well as sequence of actions
to be done.
In OOP, Importance is given to
the data rather than procedures
or functions because it works as
real world.
Approach
POP follows Top Down
approach.
OOP follows Bottom Up
approach.

Procedure Oriented Programming Object Oriented Programming
Access
Specifiers
POPdoes not have any access
specifier.
OOPhas access specifies named
Public, Private, Protected, etc.
In POP, Data can move freely
Data Moving from function to function in the
system.
In OOP, objects can move and
communicate with each other
through member functions.
Expansion
To add new data and function in
POPis not so easy.
OOPprovides an easy way to
add new data and function.

Procedure Oriented
Programming
Object Oriented
Programming
DataAccess
In POP, Most function uses
Global data for sharing that can
be accessed freely from function
to function in the system.
In OOP, data can not move
easily from function to
function,it can be kept
public or private so we can
control the access of data.
POPdoes not have any proper
OOPprovides Data Hiding
Data Hiding way for hiding data so it is less
secure.
so provides more security.
Overloading In POP, Overloading is not
possible.
In OOP, overloading is
possible in the form of
Function Overloading and
Operator Overloading.
Examples
Example of POPare : C, VB,
FORTRAN, Pascal.
Example of OOPare : C++,
JAVA, VB.NET, C#.NET.

SE-IT JAVA LAB OOP CONCEPT

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SE-IT JAVA LAB OOP CONCEPT