Autoloading
PSR-4 autoloading maps namespace prefixes to directories so you never need require or include manually.
PHP
Beginner
4 min read
PSR-4 Autoloading
Example
// composer.json
"autoload": { "psr-4": { "App\\": "src/" } }
// src/Services/EmailService.php
namespace App\Services;
class EmailService { public function send(string $to): void {} }
// Usage (after composer dump-autoload)
require "vendor/autoload.php";
use App\Services\EmailService;
$svc = new EmailService();
$svc->send("user@example.com"); Pro Tip
Run composer dump-autoload -o (optimised) in production to generate a classmap for faster loading.