How to replace characters with an asterisk in a string?

Question

PHP

There is a code:

5959067ca46f67b671340d6472fe046662fb8nc5cd338f0e449563b93a330f3ca6fe2d7m812875b473fae

You need to cut it to get this look: How to do it?
5959********3fae

Answer 1

as an option

$str = '5959067ca46f67b671340d6472fe046662fb8nc5cd338f0e449563b93a330f3ca6fe2d7m812875b473fae';
$new_str = mb_substr($str, 4) . '********' . mb_substr($str, -4);

upd:

$new_str = substr($str, 0, 4) . '********' . substr($str, -4);

Answer 2

Cut out the first 4, add the required number of stars, cut out the last 3.
Cut with substr()