March 31, 2026 in Php
11. Object-Oriented PHP (OOP)
OOP in PHP helps you write modular, reusable, and maintainable code by organizing it into objects.
🔹 1. Classes & Objects
✅ Class
A class is a blueprint/template for creating objects.
class Car {
public $name; public function start() {
echo "Car started";
}
}
✅ Object
An object is an instance of a class.
$car1 = new Car();
$car1->name = "BMW";
$car1->start();
🔹 2. Properties & Methods
- Properties → Variables inside a class
- Methods → Functions inside a class
class Student {
public $name; public function showName() {
echo $this->name;
}
}
🔹 3. Constructor & Destructor
✅ Constructor (__construct)
Runs automatically when object is created
class User {
public function __construct() {
echo "Object Created";
}
}
✅ Destructor (__destruct)
Runs when object is destroyed
class User {
public function __destruct() {
echo "Object Destroyed";
}
}
🔹 4. Inheritance
Allows one class to inherit properties & methods from another class.
class Animal {
public function sound() {
echo "Animal sound";
}
}class Dog extends Animal {
public function bark() {
echo "Bark";
}
}
🔹 5. Encapsulation
Wrapping data and restricting access using access modifiers.
Access Modifiers:
public→ accessible everywhereprivate→ only inside classprotected→ class + inherited classes
class Bank {
private $balance = 1000; public function getBalance() {
return $this->balance;
}
}
🔹 6. Polymorphism
Same function name, different behavior.
class Animal {
public function sound() {
echo "Animal sound";
}
}class Cat extends Animal {
public function sound() {
echo "Meow";
}
}
🔹 7. Traits
Traits allow code reuse (like multiple inheritance workaround).
trait Logger {
public function log($msg) {
echo $msg;
}
}class User {
use Logger;
}
🔹 8. Interfaces & Abstract Classes
✅ Interface
Only method declarations (no body)
interface Payment {
public function pay($amount);
}
✅ Abstract Class
Can have both abstract and normal methods
abstract class Shape {
abstract public function area();
}
Example:
class Circle extends Shape {
public function area() {
return 3.14 * 10 * 10;
}
}
🚀 Pro Tips (Important for Students)
✔ Use OOP for large projects
✔ Follow SOLID principles (advanced)
✔ Practice with real examples:
- User login system
- Blog system
- E-commerce cart
