What is OOP in PHP

What is OOP in PHP?

OOP (Object-Oriented Programming) in PHP is a programming approach where we organize code using objects and classes instead of writing everything as functions.

OOP helps you build clean, reusable, scalable, and maintainable applications and is mandatory knowledge for modern PHP frameworks like Laravel.

What is OOP?

Object-Oriented Programming is a concept based on:

Objects → real-world entities
Classes → blueprints of objects

Think in terms of real-life modeling (User, Product, Order).

Why Use OOP in PHP?

Better code structure
Reusability
Easy maintenance
Security (data hiding)
Required for modern frameworks

Core Concepts of OOP in PHP

There are 4 main pillars of OOP:

Class & Object
Encapsulation
Inheritance
Polymorphism

Class & Object (Basic Idea)

Class Example

Object Example

Encapsulation

Encapsulation means binding data and methods together and hiding internal details.

private data cannot be accessed directly
Improves security

Inheritance

Inheritance allows one class to inherit properties and methods from another.

Promotes code reuse

Polymorphism

Polymorphism means same method name, different behavior.

Abstraction (Bonus Concept)

Abstraction hides implementation details using abstract classes or interfaces.

OOP vs Procedural PHP (Interview)

Feature	OOP	Procedural
Structure	Organized	Linear
Reusability	High	Low
Security	High	Low
Maintenance	Easy	Hard
Framework support	Yes	No

OOP Keywords

class
object
new
public, private, protected
$this
extends
abstract
interface

Common Mistakes

Mixing procedural & OOP badly
Making everything public
Ignoring encapsulation
Not using constructors

Interview Questions & MCQs

Q1. What does OOP stand for?

A) Object Oriented Process
B) Object Oriented Programming
C) Online Object Programming
D) Object Open Programming

Answer: B

Q2. How many pillars of OOP?

A) 2
B) 3
C) 4
D) 5

Answer: C

Q3. Which concept hides data?

A) Inheritance
B) Polymorphism
C) Encapsulation
D) Abstraction

Answer: C

Q4. Which keyword is used for inheritance?

A) implements
B) extends
C) inherits
D) include