In Object-Oriented Programming (OOP), we often hear two important terms:
Class and Object.
Let us understand these terms in a very simple way.
Example: Mobile Phone
Imagine the CEO of Samsung plans to launch a new mobile phone after 2 years.
Before manufacturing starts, the CEO discusses the features and functions of the mobile with the team.
Future Mobile: Samsung SG-786
Features (Attributes)
- Screen size = 3.5 inch
- Touch screen = Yes
- Number of buttons = 7
- Charging points = 2
- Color = Red / Silver / Black
- …
(… means the list is long)
Functions (Behavior)
- Make a call
- Receive a call
- Send SMS
-
Receive SMS
- Alarm
- Calculator
- Stopwatch
- …
Class and Object Explanation
To manufacture the mobile phone, all the above details are sent to the factory.
- These specifications (features + functions) are called a Class.
- When the factory produces 10,000 mobile phones using these specifications,
each mobile phone is called an Object.
So:
- Class → Design / Blueprint / Template
- Object → Real product created from the class
One More Simple Example
Suppose you have one house blueprint.
- The blueprint is a Class
- If you build two houses using the same blueprint,
those houses are Objects
Class in Programming
When we write a program:
- Attributes are called Fields or Member Variables
- Behavior is written as Methods (Functions)
A class contains:
- Fields (data)
- Methods (actions)
An object uses the class to work.
In short:
- Class = Blueprint
- Object = Instance of the class
Hope this makes the concept of Class and Object clear for beginners.