What is a constructor and destructor in PHP?

In PHP constructors and destructors are special methods in a class that automatically run when an object is created or destroyed.

1. Constructor

Purpose: Initialize object properties or perform setup tasks when an object is created.
Special Method: __construct()
Automatically Called: As soon as you create an object using new.

Example:

<?php
class Car {
    public $brand;

    // Constructor
    public function __construct($brandName) {
        $this->brand = $brandName;
        echo "Car brand set to: {$this->brand}<br>";
    }
}

$car1 = new Car("BMW"); // Constructor is automatically called
$car2 = new Car("Audi");
?>

Output:

Car brand set to: BMW
Car brand set to: Audi

2. Destructor

Purpose: Cleanup tasks before the object is destroyed (e.g., closing database connections, freeing resources).
Special Method: __destruct()
Automatically Called: When there are no more references to the object, or at the end of the script.

Example:

<?php
class Car {
    public $brand;

    public function __construct($brandName) {
        $this->brand = $brandName;
        echo "Car brand set to: {$this->brand}<br>";
    }

    // Destructor
    public function __destruct() {
        echo "Destroying car object: {$this->brand}<br>";
    }
}

$car1 = new Car("BMW");
$car2 = new Car("Audi");
?>

Possible Output:

Car brand set to: BMW
Car brand set to: Audi
Destroying car object: BMW
Destroying car object: Audi

(Destructors may run in any order when script ends.)

Quick Difference Table

Feature	Constructor (`__construct`)	Destructor (`__destruct`)
When Called	On object creation	On object destruction/end of script
Purpose	Initialize / set up	Clean up / close resources
Parameters	Can take parameters	No parameters allowed
Return Value	Cannot return a value	Cannot return a value

🎯 Real-World Example — Booking a Hotel Room

Imagine you are checking into a hotel.

Constructor (Check-in)

When you arrive, the receptionist gives you a key, registers your name, and assigns you a room.
This is like the constructor — it sets up everything you need before you start using the room.

<?php
class HotelRoom {
    public $guestName;

    // Constructor = Check-in
    public function __construct($name) {
        $this->guestName = $name;
        echo "Welcome {$this->guestName}, your room is ready!<br>";
    }

    // Destructor = Check-out
    public function __destruct() {
        echo "Goodbye {$this->guestName}, your room is now closed.<br>";
    }
}

$guest1 = new HotelRoom("John");
$guest2 = new HotelRoom("Alice");

Possible Output:

Welcome John, your room is ready!
Welcome Alice, your room is ready!
Goodbye John, your room is now closed.
Goodbye Alice, your room is now closed.

Destructor (Check-out)

When you leave, you return the key and the hotel cleans up the room for the next guest.
This is like the destructor — it closes everything, frees resources, and does final cleanup.

✅ Key takeaway:

Constructor = Setting things up when you arrive.
Destructor = Cleaning up before you leave.