Example of Autoloading In a Legacy PHP Application

bootstrap.php

<?php
//FILE LOCATION: project-directory/config/bootstrap.php
declare(strict_types=1);

//Composer autoloader file
require_once __DIR__ . '/../vendor/autoload.php';
error_reporting(E_ALL | E_NOTICE);
//Load the files required for configuration
$configuration = require __DIR__ . '/settings.php';
$countyList = require __DIR__ . '/../vendor/some-other-package/list-of-tennessee-counties.php';

$app = \App\Application::createFromConfig($config, $counties);

unset($configuration, $counties);
return $app;

index.php

<?php
//FILE LOCATION: project-directory/public/index.php
declare(strict_types=1);

$app = require_once __DIR__ . '/../config/bootstrap.php';

/* route handling code here */