PHP bcd code compression - compress decimal numbers into hexadecimal data_PHP tutorial

Let’s take a look at the article about PHP bcd code compression - compressing decimal numbers into hexadecimal data. I hope the article will be helpful to all students.

Example, php bcd code compression - compress decimal numbers into hexadecimal data

代码如下

复制代码

/* php bcd码压缩-把十进制数字压缩到十六进制数据中 例如 0091 压缩后 0x00 0x91 */ $string = '0091'; $bytes = Bytes::getBytes($string); print_r($bytes); /* Array (     [0] => 48     [1] => 48     [2] => 57     [3] => 49 ) */ $asc=Bytes::AscToHex($bytes,4); //4位压缩成2位 print_r($asc); /* Array (     [0] => 0     [1] => 145 ) */ echo Bytes::toStr($asc); /* 0091 */ $hex=Bytes::HexToAsc($asc,2); //反操作2位还原成4位 print_r($hex); /* Array (     [0] => 48     [1] => 48     [2] => 57     [3] => 49 ) */ ?>

Example, compress decimal numbers into hexadecimal data

代码如下

复制代码

/** *php bcd code compression * Compress decimal numbers into hexadecimal data * @author phpff.com * Created on 2011-7-15 */ class Bytes {     /**       * Convert a String to a byte array       * @param $str The string to be converted       * @param $bytes target byte array       * @author phpff.com       */     public static function getBytes($string) {           $bytes = array();         for($i = 0; $i              $bytes[] = ord($string[$i]);         }         return $bytes;     }       /** ​   * Convert byte array to String type data ​   * @param $bytes byte array ​   * @param $str target string ​   * @return a String type data ​   */       public static function toStr($bytes) {         $str = '';         foreach($bytes as $ch) {             $str .= bin2hex(chr($ch));         }              return $str;     }       /** ​   * Convert asc code to hexadecimal data ​   * @param $asc asc numeric string ​   * @param $AscLen The length of the string to be converted ​   * @return hexadecimal array ​   * @author phpff.com ​   */      public static function AscToHex( $asc, $AscLen) {         $i=0;         $Hex=array();         for($i = 0; 2*$i         {             /*A:0x41(0100 0001),a:0x61(0110 0001),右移4位后都是0001,加0x90等0xa*/             $Hex[$i] =  (chr($asc[2*$i])             if (!(chr($asc[2*$i]) >= '0' && chr($asc[2*$i])                 $Hex[$i] +=  0x90;             }               if(2*$i+1 >= $AscLen){                 break;             }               $Hex[$i] |= (chr($asc[2*$i+1]) & 0x0f);             if (!(chr($asc[2*$i+1]) >= '0' && chr($asc[2*$i+1])                 $Hex[$i] += 0x09;             }           }         return $Hex;     }      /**      * 将16进制的数据转换成asc码      * @param $Hex 16进制数组      * @param $HexLen 16进制数组长度      * @return asc数组      * @author  phpff.com      */     public static function HexToAsc($Hex, $HexLen) {         $i=0;         $Temp=0;         for($i = 0; $i         {             $Temp = ($Hex[$i] & 0xf0) >> 4;             if ($Temp                 $Asc[2*$i] =  (0x30 + $Temp);             }else{                 $Asc[2*$i] =   (0x37 + $Temp);             }               $Temp = $Hex[$i] & 0x0f;             if ($Temp                 $Asc[2*$i+1] = (0x30 + $Temp);             }else{                 $Asc[2*$i+1] =  (0x37 + $Temp);             }           }         return $Asc;     }   } ?>

http://www.bkjia.com/PHPjc/633105.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/633105.htmlTechArticle下面我们一起来看和篇关于php bcd码压缩-把十进制数字压缩到十六进制数据中实例，希望文章给各位同学带来帮助哦。 例，php bcd码压缩-把十...