? PHP OOP Autoload Method

? Quick Overview

The PHP OOP Autoload method helps automatically load class files when they are needed, instead of including each file manually.

? Key Concepts

• Autoloading loads classes only when required
• Improves performance and maintainability
• Modern PHP uses spl_autoload_register()

? Syntax & Theory

The __autoload() function was used to automatically load undefined classes. However, it is deprecated since PHP 7.2.0.

Instead, spl_autoload_register() allows registering multiple autoload functions safely.

? Code Example

// Register an autoload function for loading class files
spl_autoload_register(function ($class_name) {
include $class_name . '.php';
});

// Creating an object triggers automatic loading of User.php
$obj = new User();

? Live Output / Explanation

When the User class is instantiated, PHP automatically searches for User.php and includes it without manual intervention.

? Interactive Concept

This mechanism behaves like an on-demand loader — classes are fetched only when required, reducing memory usage.

? Use Cases

• Large PHP applications with many classes
• MVC frameworks
• Composer-based dependency management