PHP implements hexadecimal conversion (binary, octal, hexadecimal) and mutual conversion code

Convert decimal to binary, octal, hexadecimal
To convert from decimal to other bases, just use the number to divide it 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 $bin 转换的进制可以是：2,8,16 
* @return array 返回数据 array() 返回没有数据转换的格式 
* @copyright chengmo QQ:8292669 
*/ 
function decto_bin($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"
}
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)
}
Later words, these It's just the implementation method. In fact, it doesn't matter whether it's PHP language or something else, 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.

For more PHP implementation of base conversion (binary, octal, hexadecimal) and mutual conversion code related articles, please pay attention to the PHP Chinese website!