PHP中二进制到十六进制转换的限制

Question

I need to convert a binary string into a hex string. This code works fine:

<?
$binary = "1111111111111111111111101000011111111111111111110000001000100100";
$hex = dechex(bindec($binary));
echo $hex;
?>

However, if I add one extra bit (or more) to the binary string, the result just comes back at 0.

<?
$binary = "11111111111111111111111101000011111111111111111110000001000100100";
$hex = dechex(bindec($binary));
echo $hex;
?>

I guess I can break up the binary string into chunks and then combine the hex value at the end, but is there any easier way?

Answer 1

Your function imlicitly converts the number to int, hitting the 32bit limit. BCMath calculates with one bit at a time and takes numbers contained in strings, so you can multiply thousands of digits.

Unfortunately there is no native BCMath function for changing a numbers base, but the needed function to do so is done in a minute. Check out the link.