- substr: documentation ( source)
- var_dump: documentation ( source)
- mb_substr: documentation ( source)
- preg_match: documentation ( source)
<?php
var_dump(substr('π',0 ,1));
var_dump(mb_substr('π', 0 , 1));
preg_match('/test/', 'πtest', $matches, PREG_OFFSET_CAPTURE);
var_dump($matches);