Delete Files recursively in PHP

I think I got this from a comment from rmdir php documentation Be careful with this one!

public static function delTree($dir) {
   $files = array_diff(scandir($dir), array('.','..'));
    foreach ($files as $file) {
      (is_dir("$dir/$file")) ? delTree("$dir/$file") : unlink("$dir/$file");
    }
    return rmdir($dir);
  }