This document discusses the key principles of object-oriented programming (OOP) including objects, classes, encapsulation, inheritance, polymorphism, and dynamic binding. It provides examples of each concept and notes that objects communicate through message passing. The benefits of OOP principles like code reuse and extensibility are highlighted. Sample applications like real-time systems and databases are also listed.

1. Principles of OOP
Presented by
D.Seethalakshmi MCA.,M.Phil.,
Assistant Professor
Bon Secours College for women
Thanjavur.

2. Principles of OOP
 Objects
 Classes
 Data abstraction and encapsulation
 Inheritance
 Polymorphism
 Dynamic binding
 Message passing

3. Objects
o The basic run time entities in object oriented system.
 It represent a person, a place, a bank account or any item that the
program has to handle.
Student
Average
Display
Total
Object: Student
DATA
Name
DOB
Marks
FUNCTIONS
Total
Average

4. Classes
 The entire set of data and code of an object can be made of user
defined data types with the help of class.
 Once class has been defined we can create number of object
belongs to that class.
 A class is a collection of object of similar data type.
 Example:
Fruit mango;

5. Data Encapsulation
 The wrapping up of data and functions into a single unit (called Class) is
known as encapsulation.
 Only access those functions which are wrapped in the class.
 The insulation of the data from direct access by the program is called
data hiding and information hiding.

6. Data Abstraction
 It represents essential features without including the background details or
explanations.
 It defined as a list of abstract attributes. Its sometime called data member
because it holds information.
 This functions are called as methods or member functions.
 Abstraction is known as Abstract Data Type(ADT)

7. Inheritance
 Inheritance is the process by which objects of one class acquire the
properties of objects of another class. It supports the concept of
hierarchical classification.
 Bird Flying bird Robin

8. Polymorphism
An operation may exhibit different
behaviors in different instances. The
behavior depends upon the types of
data used in the operation.
Polymorphism, a greek term means
ability to take more than one form.
To be continued…

9. Operator overloading &
Function overloading
 The process of making an operator to exhibit different behaviors in
different instances is known a operator overloading.
 Example: two numbers operation sum
 A single function name to perform different types of tasks is known
as function overloading.

10. Dynamic Binding
 Binding refers to the linking of a procedure call to the code to be
executed in response to the call.
 Dynamic binding (also known as late binding) means that the code
associated with a given procedure call is not known until the time of
the call at run-time.
 It is associated with polymorphism and inheritance.

11. Message passing
 An object- oriented program consists of a set of objects that
communicate with each other.
 Creating classes that define objects and their behavior
 Creating objects from class definitions
 Establishing communication among objects

12. Benefits of OOPs
 Eliminate redundant code and extend the use of exiting
classes.
 The principle of data hiding helps the programmer to build
secure programs
 It is easy to partition the work in a project based on objects.
 Object oriented systems can be easily upgraded from small
to large systems.
 Software complexity can be easily managed.

13. Applications of OOPs
 Real-time systems
 Simulation and modeling
 Object oriented databases
 Hypertext, hypermedia and expertext
 AI and expert systems
 Neural networks and parallel programming
 Decision support and office automation systems
 CIM/CAM/CAD systems

14. Simple C++ program
#include< iostream.h >
#include< conio.h >
int main( )
{
cout<< “c++ is better than c”<<endl;
getch( );
return 0;
}