This document provides an introduction to object-oriented programming (OOP). It discusses the differences between procedural programming and OOP, defining OOP as a methodology that associates data structures with operators. The core concepts of OOP are defined as objects, classes, encapsulation, inheritance, polymorphism, and message passing. Objects are instances of classes that package both data and methods. Encapsulation binds data and methods within an object, while inheritance allows classes to acquire properties from other classes in a hierarchy. Polymorphism enables different implementations through message passing between objects.

1. INTRODUCTION TO
OBJECT - ORIENTED
PROGRAMMING
PREPARED BY
Patel Shruti J.
BE- 4th sem

2. Programming Languages
• Programming languages allow programmers to code
software.
• The three major families of languages are:
– Machine languages
– Assembly languages
– High-Level languages

3. Machine Languages
• Comprised of 1s and 0s
• The “native” language of a computer
• Difficult to program – one misplaced 1 or 0 will cause
the program to fail.
• Example of code:
1110100010101 111010101110
10111010110100 10100011110111

4. Assembly Languages
• Assembly languages are a step towards easier
programming.
• Each assembly language is specific to a particular
computer architecture.
• Assembly language code needs to be translated to
machine language before the computer processes it.
• They are translated by an assembler into machine
language.
• Assembly language uses mnemonic to represent
each low level machine instruction or opcode, also
each architectural register,flag.

5. High-Level Languages
• High-level languages represent a giant leap towards
easier programming.
• The syntax of HL languages is similar to English.
• It is converted into machine level language by
compiler.
• Historically, we divide HL languages into two groups:
– Procedure oriented programming
– Object-Oriented programming (OOP)

6. Procedure oriented programming
• Early high-level languages are typically called
procedural languages.
• Procedural languages are characterized by sequential
sets of linear commands. The focus of such
languages is on structure.
• Examples include C, COBOL, Fortran, LISP, Perl,
HTML, VBScript

7. Procedure oriented programming
• Structure of POP :

8. Procedure oriented programming
• Features :
 Emphasis is on procedure of doing things.
 Larger programs are divided into smaller programs
called functions.
 Data can move openly around the system from
function to function.
 Adding of data and function is difficult.
 Top down approach in program design.

9. Object-Oriented Programming
Definition of OOP:
• Object oriented programming is a programming
methodology that associates data structures with a
set of operators which act upon it.

10. Object-Oriented Programming
• Most object-oriented languages are high-level
languages.
• The focus of OOP languages is not on structure, but
on modeling data.
• Programmers code using “blueprints” of data models
called classes.
• Examples of OOP languages include C++, Visual
Basic.NET and Java.

11. Object-Oriented Programming
• Structure of OOP :

12. Object-Oriented Programming
• Features :
 Emphasis is on data.
 Programs are divided into objects and classes.
 Data is hidden and cannot be accessed by the
external function.
 New data and functions can be added when
necessary.
 Bottom up approach in program design.

13. Elements of OOP
• Objects
• Classes
• Encapsulation
• Data Abstraction
• Inheritance
• Polymorphism
• Message Passing

14. Objects
• OOP uses objects as its fundamental building blocks.
• Objects are the basic run-time entities in an object-
oriented system.
• Every object is associated with data and functions
which define meaningful operations on that object.
• Object is a real world existing entity.
• Object is an Instance of a particular class.

15. Objects
DATAFUNCTIONS FUNCTIONS

16. Example: Student Object
St_name
St_id
Branch
Performance Result

17. Class
• Class is a collection of similar objects.
• Mango, Apple etc. are objects and their class is Fruit.

18. Encapsulation
• Wrapping up of data and functions into a single unit
(class) is called encapsulation.
• Data is not accessible to outside world.
• Only those functions which are which are wrapped in
the class can access it.

19. Data Abstraction
• A data abstraction is a simplified view of an object
that includes only features one is interested in while
hides away the unnecessary details.
• Data abstraction becomes an abstract data type
(ADT)or a user-defined type.

20. Inheritance
• Inheritance is the mechanism to provides the power
of reusability and extendibility.
• Inheritance is the process by which one object can
acquire the properties of another
object.
• Types :
 Single
 Multilevel
 Multiple
 Hybrid
 Hierarchical

21. Inheritance

22. Polymorphism
• Poly means many. Morphism means forms.
• Polymorphism means that the same thing can exist
in two forms.
• Polymorphism is in short the ability to call different
functions by just using one type of function call.
• Ex : Bank can be used as - bank (river)
- bank (finance)

23. Message Passing
• Information or message of one object can be sent to
other object.
• Object communicate with one another by sending
and receiving information much the same way as
people communicate with each other.
• A message for an object is a request for execution of
a proedure and it will invoke a procedure in receiving
object that generates the desired result.

24. Message Passing
• Message passing involves specifying the name of the
object, the name of the function and the information
to be sent.
• Ex- employee.salary(name);
Object
Message
Information

25. Benefits of OOP
• Through inheritance we can extend the use of
existing classes.
• Build secure program by data hiding.
• Message passing techniques for communication
between objects make is much simplier.
• It is easy to partition the work in a project based on
object.

26. Applications of OOP
• Database management systems
• Data security
• Artificial intelligence and expert systems
• Mobile computing
• Real time systems
• Simulation and modeling
• Distributed computing