How to remove an incomprehensible space character at the end of a word?

Question

PHP

Broke my whole head. Parsed text passed through

trim(strtolower(preg_replace("/\s+/, "", $value)));

the output is a string with an incomprehensible whitespace character at the end of the string. And the string size is 2 bytes larger

string(38) "среднеемедицинское "
string(36) "среднеемедицинское"

Where is the joint?

Answer 1

Are you sure that this character appears at the very beginning, and not somewhere after trim?

Answer 2

There is not one character, but two, as the output of var_dump()'ov directly tells you. The expression removes whitespace and nonprinting characters:
preg_replace("/\s+|/, "", $value)

Answer 3

trim(strtolower(preg_replace_all("/[^.,:-а-яА-Я0-9a-zA-Z ]+/usi", "", $value)));

Answer 4

\s+ replaces only 0x20, 0x9, 0xA, 0xD, which is directly stated in the manual. If something looks like a gap, it can safely not be. And there are also various typographic non-breaking spaces, etc.