- var_dump: documentation ( source)
- bin2hex: documentation ( source)
- str_ireplace: documentation ( source)
- setlocale: documentation ( source)
<?php
var_dump(setlocale(LC_ALL, 'de_DE.ISO-8859-1'));
echo bin2hex(str_ireplace(["\xE4", "\xF6", "\xFC"], ['1', '2', '3'], "\xE4\xC4 \xF6\xD6 \xFC\xDC")) . PHP_EOL;