php两个多维数组组合遍历

    $res = $this->LoanRecord->searchloan($conditions,$columns,$page,$this->num,$user_id);
    foreach ($res[1] as $key => $value) {
        if(!empty($value[‘b‘][‘id‘])){
            $result_day = $this->LoanRecord ->getLastDay($value[‘b‘][‘id‘]);
            $res[1][$key][‘m‘] = $result_day[‘m‘];
        }
    }