a (simpler) way to extract all characters from a UTF-8 string to array with a single call to a built-in function:
<?php
$str = 'Ма-
руся';
print_r(preg_split('//u', $str, null, PREG_SPLIT_NO_EMPTY));
?>
Output:
Array
(
[0] => М
[1] => а
[2] => -
[3] =>
[4] => р
[5] => у
[6] => с
[7] => я
)