Std 12 computer chapter 6 object oriented concepts (part 1)

Part 1
Introduction
Object | Class
Encapsulation
Abstraction
Messaging
Polymorphism Presented by Nuzhat Ibrahim Memon

• In today era of internet, website and web based
operations, rapid application development (RAD) and
reusability of source code is very important.
• Object oriented techniques as methodology or as
paradigm is playing significant role in analysis, design
and implementation of software system.
• Software developed using object-oriented are
proclaimed to be more reliable, easier to maintain,
reuse and enhance.
• Object-oriented programming concepts started
originating in the 1960s.
• Since mid 1980s, it has become the main programming
paradigm used in the creation of new software.
• Some of the popular programming languages that
support object-oriented programming are C++, Java,
C#, VB .net , ASP .net and PHP. s
NUZHAT IBRAHIM MEMON
2

Presented by Nuzhat Ibrahim Memon
3
Boil(water)
Boil(milk)
Add(sugar)
Add(tea-powder)
Stir()
Serve()
the focus is on writing
functions or procedures which operate
on data
liquid-type
powder-type
Boil (liquid-type)
Add(powder-type)
Stir()
Serve()
Function/Methods
Data/variables
Function/Procedure/Methods
The way of programming can be divided into two categories namely
the focus is on object which
contains both data and functionality together.
• The power of object-oriented programming language enables
the programmer to create modular, reusable and extendable
code.
• Object-oriented programming uses as its fundamental
building block. Similar objects are classified using a
concept of class that support object-oriented.

• in procedure oriented programming , for library
application software, we will think of all processes
of library application and focus on the modules
like student registration, book issue, book return,
fine calculation
• For library application in object oriented
programming, our focus is on the object involved
in the application. Here we think of object like
student, book and librarian. We also need to think
of association between such objects. For eg,
student returns book.
4
Library Application (POP)
Students registration()
Book issue()
Book return()
Fine calculation()
Library Application (OOP)
Students
book
Librarian
Students registration()
Book issue()
Book return()
Fine calculation()

Abstraction
Encapsulation
Polymorphism
Inheritance
5
A computer language is object-oriented if they support
four specific object properties
4 Pillars of OOPs (A PIE)

• In the real world, objects are the entities of which the world is comprised.
• Some objects can be concrete things like person, car or a coffee cup.
While other objects may be abstract that do not represent things which can
be touched or seen; for example, concept like date and time.
6
Real world entities
Instance of class

Attributes / Properties / Data Fields
• All objects have unique identity and are distinguishable from each
other. In object-oriented terminology, such characteristics are
known as properties or attributes.
• In object oriented programming, attributes that describe the object
are also referred to as data fields.
• To uniquely identify the object, the value of these attributes are
used. These values are called State.
• State is used to distinguish objects from each other.
Behaviour
• Additionally the behaviour associated with objects. The behaviour is
also known as method.
Members or Features
• The data attributes and behavioral methods associated with an
object are collectively referred to as its members or features.
7
Name: Bob
City: Pune
Gender: Male
Birthdate: 1st March
Profession: Doctor
Name: Lily
City: Delhi
Gender: Female
Birthdate: 2nd May
Profession:Teacher
Name: xyz
Color: Blue
Model: xyz 2020
Manfacture: Honda
Name: abc
Color: Pink
Model: abc 2021
Manufacture: BMW

8
• Class can be considered as a blueprint for various objects.
• A class is a template for multiple objects with similar
features.
• It describes a group of objects with similar attributes and
common behavior. Similar objects are classified using a
concept of class.
• Objects in the same class share a common semantic
purpose.
• Thus, the class is a general concept used to embody all the
common features of a particular set of objects.
‘Car’

9
• For example, we have a class named
‘Person’ describing common attributes
and behaviors of all persons.
• In ’Person’ class , individual persons
are considered as objects and are
identified by the state; that is the value
of their attributes
Objects
Class
Few More Examples:
Class: Human Object: Man, Woman
Class: Animal Object: Cat, Dog, Rabbit
Class: Fruit Object: Apple, Mango, Kiwi

• For any computer program, two core elements are data and
function.
• Structured/ procedural programming views these two core
element as two separate entities;
whereas object-oriented programming views them as single
entity.
• In procedural programming, data can be altered by any
component of the program. It is not protected from modification.
• In Object Oriented Programming, this problem can be solved
using encapsulation.
10
Data
Data
Data
Procedure
Programming
Object 2
Object 1
Object 3
Data
Data Data
Object Oriented
Programming

• Data and method that manipulate data are guarded against modification or
misuse by other components of the program.
• This mechanism of providing protection to data and methods of a program is
called encapsulation.
• This is possible by wrapping data and methods into a single unit known as
class and declaring them as private.
• Private members of the class are not available directly to outside world. If
necessary , the data is made available via public methods.
• Thus, encapsulation provides data hiding capabilities.
• Encapsulation keeps the data safe from unintended actions and inadvertent
access by outside objects.
11
Class
Data /
Variable
Function /
Methods/
Behavior

• Data abstraction is a process of representing the essential features of the objects
without including implementation detail.
• Abstraction is a concept that hides complexity; it says what it does, but not how it
is done.
• Data abstraction is a technique that relies on the separation of interface and
implementation.
• Data abstraction provides the skeleton or templates for our use.
• The system hides certain details of how data is stored, created and maintained.
• Examples of data abstraction
• Abstract Data Types(ADT) or Structures (struct) in C/C++
• classes in C++/Java
• In ADT, we simply define a data type and set of operation on it. We do not show the
implementation of operations.
12

• Encapsulate protects data by making them
inaccessible from outside.
• Abstraction enables to represent data in which the
implementation details are hidden (abstracted).
13

• Different classes may have same methods with same name.
• Date class->display() , display the date object in
specific format
• Time class->display(), to display time in specific format
• person class -> display() to display the details of
person
• In object-oriented termixnology, a call to a method is
referred to as a message.
• When method ‘display’ is invoked in the program, how to
know which method is to be executed?
• This is determined using the object that invokes the method.
• Due to encapsulation, all method calls are handled by
objects that recognize the method
• For eg. If ‘display’ is called by an object of ‘person’ class, it
executes the display method defined in ‘person’ class.
14
class date class time class person
void display(){
System.out.println
(“Display the date
object in specific
format”);
}
void display(){
System.out.println
(“Display the
time in specific
format”);
}
void display(){
System.out.println
(“Display the
details of
person”);
}
date d_obj = new date();
time t_obj = new time();
person p_obj = new person();
d_obj.display();
t_obj,display();
p_obj.display();

15
• Polymorphism means ‘many forms’.
• The polymorphism is achieved using two type of overloading: function overloading and operator
overloading.
• The capability of using same names to mean different things in different contexts is called overloading.
Operator
Overloading
Function
Overloading
Polymorphism

16
• Function or method overloading
• It is possible to define more than one function with the same name in
object-oriented programming.
• The methods differs in signatures( number and type of parameters)
• Object- oriented programming allows defining more than one method
having same name but different signatures in a single class. This
feature is known as function or method overloading.
• Operator overloading
• Object oriented programming also allows writing expression using
operators on objects.
• Date d1 – date d2 and n1- n2; operator ‘-’ is performing in a different
way.
• The same operation is given different meanings upon the data type of
operands used. This type of polymorphism is achieved through
operator overloading.
Operator ‘+’
2 + 2 = 4 ‘in’ + ‘dia’ = ‘India’
Operator ‘-’
n1 - n2 date d1 – date d2
Area (l,w)
Area
(pi,r,r)
Shape
Area
( *b*h)
Max (int, int){
return int;
}
Max (array, size){
return int;
}

Nuzhat Memon
website:
nuzhatmemon.com
Email:
nuzhat.memon@gmail.com

Std 12 computer chapter 6 object oriented concepts (part 1)

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Std 12 computer chapter 6 object oriented concepts (part 1)