PHP 打印二进制形式介绍 $row[permission]=u;// or =chr(117) echo " id = " . str_pad(decbin(ord($row[permission])),8,0,STR_PAD_LEFT); echo " id = "; printf("%08b ",ord($row[permission])); ?> 输出: id = 01110101 id = 1110101 printf解释:% :占位符0:用0填充未满的宽度8 :共要8位b :二进制模式