array_multisort()&&preg_match中文.php

$data = $taobaoapi->allQuanList($q,$p, 100, $platform, $cat, $pid);
$ret_tmp = objtoarr($data);
$ret_tmp_tbk_coupon = $ret_tmp['results']['tbk_coupon'];
$sort = [];
foreach ($ret_tmp_tbk_coupon as $k=>$v){
    $ret_tmp_tbk_coupon[$k]['sales'] =  $v['coupon_total_count'] - $v['coupon_remain_count'];

//            $ret_tmp_tbk_coupon[$k]['coupon_price'] =  substr($v['coupon_info'],strpos($v['coupon_info'],'减')-1,-1);
    preg_match("/[\x{4e00}-\x{9fa5}]{2,4}(\d+)/u", $v['coupon_info'], $matches);
    $ret_tmp_tbk_coupon[$k]['coupon_price'] = $matches[1];
    $ret_tmp_tbk_coupon[$k]['discount'] =  sprintf('%.3f',$matches[1]/$ret_tmp_tbk_coupon[$k]['zk_final_price']);
}
$sort = [1=>'sales',2=>'discount',3=>'zk_final_price',4=>'coupon_price'];
$sort_type = [1=>SORT_DESC,2=>SORT_DESC,3=>SORT_ASC,4=>SORT_DESC];
foreach ($ret_tmp_tbk_coupon as $key => $row) {
    $sales[$key]  = $row['sales'];
    $discount[$key] = $row['discount'];
    $zk_final_price[$key] = $row['zk_final_price'];
    $coupon_price[$key] = $row['coupon_price'];
}

        $tmp = $sort[$s];
        $b = $$tmp;

        array_multisort($$tmp, $sort_type[$s],  $ret_tmp_tbk_coupon);