PHP Classes and Objects Tutorial: A Beginner-Friendly Guide

Object-Oriented Programming (OOP) in PHP starts with classes and objects. These are the building blocks for creating structured, maintainable, and reusable code.

In this tutorial, you will learn:

What a class is
What an object is
How to create classes and objects in PHP
How to define properties and methods
How to use constructors
Real-world developer examples

🔹 What Is a Class?

A class is a blueprint or template used to create objects. It defines:

Properties (variables)
Methods (functions)

Example: A class that represents a Car.

🔹 What Is an Object?

An object is an instance of a class.
It represents a real entity created from the blueprint.

Example: $car1, $car2 are objects of the class Car.

🔸 1. Creating a Simple Class and Object

<?php
class Car {
    public $brand;
    public $color;

    public function start() {
        echo "Car is starting...";
    }
}

$myCar = new Car();
$myCar->brand = "Tata";
$myCar->color = "Red";

echo $myCar->brand;       // Output: Tata
$myCar->start();          // Output: Car is starting...
?>

🔸 2. Properties and Methods

Properties → Variables inside class
Methods → Functions inside class

Example:

class Student {
    public $name;
    public $age;

    public function introduce() {
        echo "My name is " . $this->name;
    }
}

$st = new Student();
$st->name = "Shubham";
$st->introduce();

🔸 3. Using `$this` Keyword

$this refers to the current object.

Used to access class properties and methods from inside the class.

🔸 4. Constructors in PHP (`__construct`)

A constructor runs automatically when an object is created.

class User {
    public $name;

    public function __construct($name) {
        $this->name = $name;
        echo "User created: $name";
    }
}

$u = new User("Amit");

🔸 5. Real-World Example: Product Class

class Product {
    public $name;
    public $price;

    public function __construct($name, $price) {
        $this->name = $name;
        $this->price = $price;
    }

    public function getDetails() {
        return $this->name . " - Rs. " . $this->price;
    }
}

$p = new Product("Laptop", 55000);
echo $p->getDetails();

🔸 6. Multiple Objects from Same Class

$car1 = new Car();
$car1->brand = "Tata";

$car2 = new Car();
$car2->brand = "Mahindra";

Each object has its own properties.

🔸 7. Class with Default Property Values

class Animal {
    public $type = "Dog";
}

$a = new Animal();
echo $a->type;   // Dog

🔸 8. Methods with Parameters

class MathOperations {
    public function add($a, $b) {
        return $a + $b;
    }
}

$m = new MathOperations();
echo $m->add(10, 20);

9. Combining Everything: User Profile Example

class UserProfile {
    public $name;
    public $email;

    public function __construct($name, $email) {
        $this->name = $name;
        $this->email = $email;
    }

    public function showProfile() {
        echo "Name: {$this->name}<br>Email: {$this->email}";
    }
}

$user = new UserProfile("Shubham", "shubham@example.com");
$user->showProfile();

Summary

You learned:

What classes and objects are
How to define properties and methods
How to use constructors
How to create real-world OOP examples

Classes and objects are the foundation of OOP in PHP.