What is OOP in PHP

PHP Tutorial

🧠 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.

1️⃣ 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).

2️⃣ Why Use OOP in PHP?

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

3️⃣ Core Concepts of OOP in PHP ⭐

There are 4 main pillars of OOP:

  1. Class & Object

  2. Encapsulation

  3. Inheritance

  4. Polymorphism

4️⃣ Class & Object (Basic Idea)

Class Example


 

Object Example


5️⃣ Encapsulation ⭐

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

class Account {
private $balance = 0;public function deposit($amount) {
$this->balance += $amount;
}public function getBalance() {
return $this->balance;
}
}

✔ private data cannot be accessed directly
✔ Improves security

6️⃣ Inheritance ⭐

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

class Person {
public $name;
}class Student extends Person {
public $marks;
}

✔ Promotes code reuse

7️⃣ Polymorphism ⭐

Polymorphism means same method name, different behavior.

class Shape {
function area() {}
}class Circle extends Shape {
function area() {
return “Circle area”;
}
}class Square extends Shape {
function area() {
return “Square area”;
}
}

8️⃣ Abstraction (Bonus Concept)

Abstraction hides implementation details using abstract classes or interfaces.

abstract class Vehicle {
abstract function move();
}class Car extends Vehicle {
function move() {
echo “Car moves”;
}
}

9️⃣ 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 in PHP

  • class

  • object

  • new

  • public, private, protected

  • $this

  • extends

  • abstract

  • interface

1️⃣1️⃣ 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

✅ Answer: B

Q5. Which PHP feature supports multiple inheritance?

A) Classes
B) Interfaces
C) Traits
D) Objects

✅ Answer: B
(Also Traits, but interfaces are commonly asked)

🔥 Real-Life Use Cases

✔ MVC frameworks
✔ Large web applications
✔ APIs
✔ Enterprise software
✔ Reusable libraries

✅ Summary

  • OOP structures PHP code using classes & objects

  • Based on 4 pillars

  • Improves security, reusability, maintenance

  • Mandatory for modern PHP development

  • Very important for interviews & real projects

You may also like...