- var_dump: documentation ( source)
- bin2hex: documentation ( source)
- mb_substr: documentation ( source)
- hexdec: documentation ( source)
- mb_internal_encoding: documentation ( source)
<?php
mb_internal_encoding("UTF-8");
$string = "\0";
$char = mb_substr($string, 0, 1);
var_dump(bin2hex($char)); //hex
var_dump(hexdec(bin2hex($char))); //decimal