note 83122 modified in function.dechex by danbrown
| From: | danbrown@php.net | Date: | Tue, 16 Feb 2010 23:27:30 +0000 |
| Subject: | note 83122 modified in function.dechex by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-166036@lists.php.net to get a copy of this message | ||
I was challenged by a problem with large number calculations and conversion to hex within php. The
calculation exceeded unsigned integer and even float range. You can easily change it for your needs
but it is, thanks to bcmath, capable of handling big numbers via string. This function will convert
them to hex.
In this specific example though, since I use it for game internals that can only handle 32 bit
numbers, it will truncate calculations at 8 digits. If the input is 1 for example it will be filled
up with zeros. Output 00000001h.
Of course I don't claim it to be a good one, but it works for me and my purpose. Suggestions on
faster code welcome!
<?php
// Turns numbers into 32-bit hex string; Fills up zeros
function lrgDec2Hex($number)
{
$i = 0;
$hex = array();
while($i < 8) {
if($number == 0) {
array_push($hex, '0');
}
else {
array_push($hex, strtoupper(dechex(bcmod($number, '16'))));
$number = bcdiv($number, '16', 0);
}
$i++;
}
krsort($hex);
return implode($hex);
}
?>
--was--
I was challenged by a problem with large number calculations and conversion to hex within php. The
calculation exceeded unsigned integer and even float range. You can easily change it for your needs
but it is, thanks to bcmath, capable of handling big numbers via string. This function will convert
them to hex.
In this specific example though, since I use it for game internals that can only handle 32 bit
numbers, it will truncate calculations at 8 digits. If the input is 1 for example it will be filled
up with zeros. Output 00000001h.
Of course I don't claim it to be a good one, but it works for me and my purpose. Suggestions on
faster code welcome!
// Turns numbers into 32-bit hex string; Fills up zeros
function lrgDec2Hex($number)
{
$i = 0;
$hex = array();
while($i < 8) {
if($number == 0) {
array_push($hex, '0');
}
else {
array_push($hex, strtoupper(dechex(bcmod($number, '16'))));
$number = bcdiv($number, '16', 0);
}
$i++;
}
krsort($hex);
return implode($hex);
}
http://php.net/manual/en/function.dechex.php