Day-56 Understanding OOPS Concepts in Java

Today in our Java class, we discussed the fundamentals of Object-Oriented Programming (OOP). Here is my detailed summary

What is OOP?

OOP stands for Object-Oriented Programming, a paradigm (idea) used in languages like:

• Java
• C++
• Python

It focuses on creating objects and classes to organize and structure the code efficiently.

Core OOPS Concepts

1. Object

• An instance of a class.
• Has state(data/properties) and behaviour (methods/functions).
• Example: A car is an object. Its state is colour, model; behaviour is drive, brake.

2. Class

• A blueprint or template to create objects.
• Example: A movie class can create different movie objects.

POP vs OOP

POP	OOP
Procedure Oriented Programming	Object Oriented Programming
Focuses on functions (procedures)	Focuses on objects and classes
Example: C	Example: Java

3. Encapsulation

• Binding code and data together in a single unit.
• Prevents outside classes from directly accessing data.
• Example: Car – you use drive(), but don’t know the internal engine details.

4. Abstraction

• Showing only necessary details and hiding the unwanted complexity.
• Example: Car – you see steering, pedals, dashboard; internal wiring is hidden.

5. Inheritance

• One class can inherit properties and behaviours from another class.
• Promotes code reusability.
• Example: Child class inherits from Parent class (eg: Parent → Child).

6. Polymorphism

• One interface, many forms.
• The same function or method behaves differently in different situations.
• Example: Like us – at work we do different tasks, at home we do different tasks. One person, different roles.

Java Naming Rules for Classes

• Always start with a capital letter
• Name should be meaningful
• No spaces allowed
• No special characters (except _ or $)
• Numbers can be used but not at the beginning(only in middle or end)