php如何改变数组键名

$ar = array(
 array(1 => 'a', 2 => 50, 3 => 60, 4 => 'long', 5 => 'zzz', 6 => 'kkk', 7 => 'ooo'),
 array(1 => 'b', 2 => 60, 3 => 70, 4 => 'king', 5 => 'lll', 6 => 'ttt', 7 => 'ppp'),
 array(1 => 'c', 2 => 70, 3 => 80, 4 => 'quit', 5 => 'qqq', 6 => 'xxx', 7 => 'ccc'),
);
$kname = array('StaffId', 'Wage', 'Name', 'Work', 'Type');
function foo(&$v, $k, $kname) {
 $v = array_combine($kname, array_slice($v, 1, -1));
}
array_walk($ar, 'foo', $kname);
print_r($ar);

Array
(
  [0] => Array
    (
      [StaffId] => 50
      [Wage] => 60
      [Name] => long
      [Work] => zzz
      [Type] => kkk
    )
  [1] => Array
    (
      [StaffId] => 60
      [Wage] => 70
      [Name] => king
      [Work] => lll
      [Type] => ttt
    )
  [2] => Array
    (
      [StaffId] => 70
      [Wage] => 80
      [Name] => quit
      [Work] => qqq
      [Type] => xxx
    )
)