php 字符串固定长度，不够补充其他字符串

// str_pad(带填补的字符串,填补后的长度，填补字符串，填补位置)

 $result=["7","6","8","4","3","23","27","9","5","19","10","21"];

 if($result){

    foreach ($result as $key => $value){

        $result[$key]=str_pad($value,2,0,STR_PAD_LEFT);

    }

 //$result =["07","06","08","04","03","23","27","09","05","19","10","21"]