UNIT I
OBJECT-ORIENTED PROGRAMMING
Object-Oriented Programming or OOPs refers to languages that uses objects in programming. Object-
oriented programming aims to implement real-world entities like inheritance, hiding, polymorphism
etc in programming. The main aim of OOP is to bind together the data and the functions that operate
on them so that no other part of the code can access this data except that function. Object-Oriented
Programming is a methodology or paradigm to design a program using classes and objects. It
simplifies software development and maintenance by providing some concepts:
Object
Class
Inheritance
Polymorphism
Abstraction
Encapsulation
Object Oriented Programming popularly known as OOP, is used in a modern programming language
like Java
CORE OOPS CONCEPTS (PRINCIPLES OF OBJECT ORIENTATION-CLASS)
1) Class
The class is a group of similar entities. It is only a logical component and not the physical entity. For
example, if you had a class called “Expensive Cars” it could have objects like Mercedes, BMW,
Toyota, etc. Its properties (data) can be price or speed of these cars. While the methods may be
performed with these cars are driving, reverse, braking etc.
2) Object
An object can be defined as an instance of a class, and there can be multiple instances of a class in a
program. An Object contains both the data and the function, which operates on the data. For example
- chair, bike, marker, pen, table, car, etc.
An object consists of:
1. State : It is represented by attributes of an object. It also reflects the properties of an object.
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Page
, 2. Behavior : It is represented by methods of an object. It also reflects the response of an object
with other objects.
3. Identity : It gives a unique name to an object and enables one object to interact with other
objects.
What are Classes and Objects?
Classes and objects are the two main aspects of object-oriented programming.Look at the following
illustration to see the difference between class and objects:
CLASS
Fruit
OBJECTS
Apple
Banana
Mango
3) Inheritance
Inheritance is an OOPS concept in which one object acquires the properties and behaviors of the parent
object. It’s creating a parent-child relationship between two classes. It offers robust and natural
mechanism for organizing and structure of any software.
4) Polymorphism
Polymorphism refers to the ability of a variable, object or function to take on multiple forms. For
example, in English, the verb run has a different meaning if you use it with a laptop, a foot race,
and business. Here, we understand the meaning of run based on the other words used along with it.
The same also applied to Polymorphism.
2 Page
OBJECT-ORIENTED PROGRAMMING
Object-Oriented Programming or OOPs refers to languages that uses objects in programming. Object-
oriented programming aims to implement real-world entities like inheritance, hiding, polymorphism
etc in programming. The main aim of OOP is to bind together the data and the functions that operate
on them so that no other part of the code can access this data except that function. Object-Oriented
Programming is a methodology or paradigm to design a program using classes and objects. It
simplifies software development and maintenance by providing some concepts:
Object
Class
Inheritance
Polymorphism
Abstraction
Encapsulation
Object Oriented Programming popularly known as OOP, is used in a modern programming language
like Java
CORE OOPS CONCEPTS (PRINCIPLES OF OBJECT ORIENTATION-CLASS)
1) Class
The class is a group of similar entities. It is only a logical component and not the physical entity. For
example, if you had a class called “Expensive Cars” it could have objects like Mercedes, BMW,
Toyota, etc. Its properties (data) can be price or speed of these cars. While the methods may be
performed with these cars are driving, reverse, braking etc.
2) Object
An object can be defined as an instance of a class, and there can be multiple instances of a class in a
program. An Object contains both the data and the function, which operates on the data. For example
- chair, bike, marker, pen, table, car, etc.
An object consists of:
1. State : It is represented by attributes of an object. It also reflects the properties of an object.
1
Page
, 2. Behavior : It is represented by methods of an object. It also reflects the response of an object
with other objects.
3. Identity : It gives a unique name to an object and enables one object to interact with other
objects.
What are Classes and Objects?
Classes and objects are the two main aspects of object-oriented programming.Look at the following
illustration to see the difference between class and objects:
CLASS
Fruit
OBJECTS
Apple
Banana
Mango
3) Inheritance
Inheritance is an OOPS concept in which one object acquires the properties and behaviors of the parent
object. It’s creating a parent-child relationship between two classes. It offers robust and natural
mechanism for organizing and structure of any software.
4) Polymorphism
Polymorphism refers to the ability of a variable, object or function to take on multiple forms. For
example, in English, the verb run has a different meaning if you use it with a laptop, a foot race,
and business. Here, we understand the meaning of run based on the other words used along with it.
The same also applied to Polymorphism.
2 Page
