php二维数组排序

$arr[1]['name']='a';
$arr[1]['chinese']=5;
$arr[2]['name']='b';
$arr[2]['chinese']=56;

$arr[3]['name']='c';

$arr[3]['chinese']=1;



usort($arr, function($a, $b) {
      $al = strlen($a['chinese']);
      $bl = strlen($b['chinese']);
      if ($al == $bl)
        return 0;
      return ($al > $bl) ? -1 : 1;
    });
var_dump($arr);