php 实现进制相互转换_php技巧

WBOY
Release: 2016-05-16 19:54:35
Original
1394 people have browsed it

从十进制向其它进制转换,用的是就用该数字不断除以要转换的进制数,读取余数。连接一起就可以了。

<&#63;php 
/**
 *十进制转二进制、八进制、十六进制 不足位数前面补零*
 *
 * @param array $datalist 传入数据array(100,123,130)
 * @param int $bin 转换的进制可以是:2,8,16
 * @return array 返回数据 array() 返回没有数据转换的格式
 */
function decto_bin($datalist,$bin)
{
  static $arr=array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F');
  if(!is_array($datalist)) $datalist=array($datalist);
  if($bin==10)return $datalist; //相同进制忽略
  $bytelen=ceil(16/$bin); //获得如果是$bin进制,一个字节的长度
  $aOutChar=array();
  foreach ($datalist as $num)
  {
    $t="";
    $num=intval($num);
  if($num===0)continue;
    while($num>0)
    {
      $t=$arr[$num%$bin].$t;
      $num=floor($num/$bin);
    }
    $tlen=strlen($t);
    if($tlen%$bytelen!=0)
    {
    $pad_len=$bytelen-$tlen%$bytelen;
    $t=str_pad("",$pad_len,"0",STR_PAD_LEFT).$t; //不足一个字节长度,自动前面补充0
    }
    $aOutChar[]=$t;
  }
  return $aOutChar;
}

Copy after login

测试:

var_dump(decto_bin(array(128,253),2));
var_dump(decto_bin(array(128,253),8));
var_dump(decto_bin(array(128,253),16));

X-Powered-By: PHP/5.2.0
Content-type: text/html

array(2) {
 [0]=>
 string(8) "10000000"
 [1]=>
 string(8) "11111101"
}
array(2) {
 [0]=>
 string(4) "0200"
 [1]=>
 string(4) "0375"
}
array(2) {
 [0]=>
 string(2) "80"
 [1]=>
 string(2) "FD"
}

Copy after login

二进制、八进制、十六进制转十进制

这个转换用乘法,如:1101 转十进制:1*2^3+1*2^2+0*2^1+1*2^0

代码:

<&#63;php 
/**
 *二进制、八进制、十六进制 转十进制*
 *
 * @param array $datalist 传入数据array(df,ef)
 * @param int $bin 转换的进制可以是:2,8,16
 * @return array 返回数据 array() 返回没有数据转换的格式
 * @copyright chengmo QQ:8292669
 */
function bin_todec($datalist,$bin)
{
  static $arr=array('0'=>0,'1'=>1,'2'=>2,'3'=>3,'4'=>4,'5'=>5,'6'=>6,'7'=>7,'8'=>8,'9'=>9,'A'=>10,'B'=>11,'C'=>12,'D'=>13,'E'=>14,'F'=>15);
  if(!is_array($datalist))$datalist=array($datalist);
  if($bin==10)return $datalist; //为10进制不转换
  $aOutData=array(); //定义输出保存数组
  foreach ($datalist as $num)
  {
    $atnum=str_split($num); //将字符串分割为单个字符数组
    $atlen=count($atnum);
    $total=0;
    $i=1;
    foreach ($atnum as $tv)
    {
      $tv=strtoupper($tv);
       
      if(array_key_exists($tv,$arr))
      {
        if($arr[$tv]==0)continue;
        $total=$total+$arr[$tv]*pow($bin,$atlen-$i);
      }
      $i++;
    }
    $aOutData[]=$total;
  }
  return $aOutData;
}
 

Copy after login

测试:

var_dump(bin_todec(array('ff','ff33','cc33'),16));
var_dump(bin_todec(array('1101101','111101101'),2));
var_dump(bin_todec(array('1234123','12341'),8));

X-Powered-By: PHP/5.2.0
Content-type: text/html

array(3) {
 [0]=>
 int(255)
 [1]=>
 int(65331)
 [2]=>
 int(52275)
}
array(2) {
 [0]=>
 int(124)
 [1]=>
 int(508)
}
array(2) {
 [0]=>
 int(342099)
 [1]=>
 int(5345)
}

Copy after login

这些只是实现方式,其实不在乎php语言还是其它,实现思路都是一样的。php其实内置不少函数可以完成这些内容:

bindec(),decoct(),dechex() base_convert() decbin() 这里只是实现思路而已。呵呵!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!