PHP implements hexadecimal conversion

To convert from decimal to other bases, just divide the number by the base number to be converted and read the remainder. Just connect them together.

<?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 $arr=array(0,1,2,3,4,5,6,7,8,9,&#39;A&#39;,&#39;B&#39;,&#39;C&#39;,&#39;D&#39;,&#39;E&#39;,&#39;F&#39;);
  if(!is_array($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;
}

Test:

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"
}

Convert binary, octal, hexadecimal to decimal

This conversion uses multiplication, such as: 1101 to decimal: 1*2^3+1*2^2+0*2^1+ 1*2^0

Code:

<?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 $arr=array(&#39;0&#39;=>0,&#39;1&#39;=>1,&#39;2&#39;=>2,&#39;3&#39;=>3,&#39;4&#39;=>4,&#39;5&#39;=>5,&#39;6&#39;=>6,&#39;7&#39;=>7,&#39;8&#39;=>8,&#39;9&#39;=>9,&#39;A&#39;=>10,&#39;B&#39;=>11,&#39;C&#39;=>12,&#39;D&#39;=>13,&#39;E&#39;=>14,&#39;F&#39;=>15);
  if(!is_array($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;
}

Test:

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)
}

These are just implementation methods. In fact, it doesn’t matter whether it is PHP language or other, the implementation ideas are the same. PHP actually has many built-in functions to complete these contents:

bindec(), decoct(), dechex() base_convert() decbin() This is just an implementation idea.

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