mandatory basic knowledge of object oriented programming before you start

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