Why is preg_replace not working correctly in php?

Question

PHP

I use this regular expression to clean up Cyrillic: https://regex101.com/r/NQQXSN/1

Judging by the site, everything works OK, it finds what it needs.

I use in code:

$string = '157AF0_УЦЕНКА';
preg_replace('/[\x{0410}-\x{042F}]+.*[\x{0410}-\x{042F}]+/iu', '', $string);
dump($string); // output "157AF0_УЦЕНКА"

Finds and replaces absolutely nothing. wtf? Why is this happening? I don't understand.

Answer 1

$string = preg_replace('/[\x{0410}-\x{042F}]+.*[\x{0410}-\x{042F}]+/iu', '', $string);