Array nach Anfangsbuchstaben sortieren

//Drücken Sie den ersten Buchstaben
foreach ($res as $k => $v)
{
$res[$k]['first'] = strtoupper(substr(trim( $v['name']), 0, 1));
                    $arr = array('A', 'B', 'C', 'D', 'E', 'F', 'G' , 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', ' T', 'U', 'V', 'W', 'X', 'Y', 'Z');
                                                                                                             // If (! in_array($res[$k]['first'], $arr))
                                                                            res as $k => $v)
> 


 ksort($result);