This document discusses object-oriented programming (OOP) and its key concepts. It outlines the evolution from procedural programming to OOP, which treats data as critical elements tied to functions through classes. Some key benefits of OOP include reusability, inheritance, polymorphism, and encapsulation. Popular OOP languages include C++, Smalltalk, and Java, with C++ becoming an industry standard.

1. PRINCIPLES OF OBJECT
ORIENTED PROGRAMMING

2. KEY CONCEPTS
 SOFTWARE EVOLUTION
 PROCEDURE ORIENTED PROGRAMMING
 OBJECT ORIENTED PROGRAMMING
 OBJECTS
 CLASSES
 DATA ABSTRACTION
 ENCAPSULATION
 INHERITANCE
 POLYMORPHISM
 DYNAMIC BINDING
 MESSAGE PASSING
 OBJECT ORIENTED LANGUAGES
 OBJECT BASED LANGUAGES

3. SUMMARY
 Software technology has evolved through a series of phases during the
last five decades.
 The most popular phase till recently was procedure oriented
programming(POP).
 POP employs top down programming approach where a problem is
viewed as a sequence of tasks to be performed. A number of functions
are written to implement these tasks.
 POP has two major drawbacks, viz (1) data move freely around the
program and are therefore vulnerable to the changes caused by any
functions in the program and (2) it does not model well the real-world
problems.
 Object Oriented Programming(OOP) was invented to overcome the
drawbacks of the POP. It employs the bottom-up programming approach.
It treats data as a critical element in the program development and does
not allow it to move freely around the system. It ties data more closely to
the functions that operate on it in a data structure called class. This
feature is called data encapsulation .
 In OOP, a problem is considered as a collection of number of entities
called objects. Objects are instances of classes.

4. SUMMARY CONTD
 Insulation of data from direct access by the program is called data hiding.
 Data abstraction refers to putting together essential features without including
background details.
 Inheritance is a process by which objects of one class acquire the properties of
objects of another class.
 Polymorphism means one name , multiple forms. It allows us to have more than
one functions with same function name in a program. It also allows overloading of
operators so that an operation can exhibit different behaviors in different
instances.
 Dynamic Binding means that the code associated with a given procedure is not
known until the time of the call at run-time.
 Message Passing involves specifying the name of the object , the name of the
function (message) and the information to be sent.
 Object-oriented technology offers several benefits over the conventional
programming methods-the most important one is being the reusability.
 Applications of OOP technology has gained importance in almost all areas of
computing including real-time business systems.
 There are a number of languages that support object-oriented programming
paradigm. Popular among them are C++,Smalltalk and Java. C++ has become
industry standard language today.

5. KEY TERMS
 Ada
 assembly language
 Bottom up programming
 C++
 Classes
 Concurrency
 Data abstraction
 Data encapsulation
 Data hiding
 Data members
 Dynamic binding
 Early binding
 Eiffel
 Flowcharts
 Function overloading
 Functions
 Garbage collection
 Global data

6. KEY TERMS CONTD
 Hierarchical classification
 Inheritance
 Java
 Late binding
 Local data
 Machine language
 Member functions
 Message passing
 Methods
 Modular programming
 Multiple inheritance
 Object libraries
 Object Pascal
 Object-based programming
 Objective C
 Object -oriented languages
 Object -oriented programming
 Objects
 Operator overloading
 Persistence

7. KEY TERMS CONTD
 Polymorphism
 Procedure-oriented programming
 Reusability
 Simula
 Smalltalk
 Structured programming
 Top-down programming
 Turbo Pascal

8. REFERENCES
OBJECT ORIENTED PROGRAMMING WITH C++
-E. Balagurusamy