Own autoloader with multiple directorys

Own autoloader with multiple directorys

<?php
class Autoloader
{
    public static function register()
    {
        spl_autoload_register(function ($class) {
            $ff = str_replace('\\', DIRECTORY_SEPARATOR, $class);
            $Class_Dirs = array (
                "/Class/",
                "/Controllers/",
                "/Controllers/Content/",
            );
            for ($i = 0; $i < count($Class_Dirs); $i++)
            {
                $file = $_SERVER["DOCUMENT_ROOT"].$Class_Dirs[$i].$ff.'.php';
                if (file_exists($file))
                {
                    require $file;
                    return true;
                }
            }
            return false;
        });
    }
}
Autoloader::register();