- array_map: documentation ( source)
- var_dump: documentation ( source)
- decbin: documentation ( source)
- implode: documentation ( source)
- str_split: documentation ( source)
- ord: documentation ( source)
<?php
$str = chr(4) . chr(53) . chr(124);
var_dump(implode(array_map(function($c) { return decbin(ord($c)); }, str_split($str))));