When working with preg_replace, the element that I want to pull out of the line does not come out, what could be the problem?

Question

PHP

I am writing my router for custom routing on the site. There was such a problem:
When running the following script, I do not get data from the string after applying the regular expression in preg_replace:

$pattern_regex = preg_replace("/\{(.*?)\}/", "(?P<$1>[\w-]+)", $pattern);
$pattern_regex = "#^" . $pattern_regex . "$#";
var_dump($pattern_regex);

The data that goes into the $pattern variable :

/home
/user
/user/profile/{id}
/user/{id}/edit

Should be:

string(9) "#^/home$#"
string(9) "#^/user$#"
string(32) "#^/user/profile/(?P<id>[\W-]+)$#"
string(29) "#^/user/(?P<id>[\W-]+)/edit$#"

The following comes out:

string(9) "#^/home$#"
string(9) "#^/user$#"
string(32) "#^/user/profile/(?P[\W-]+)$#"
string(29) "#^/user/(?P[\W-]+)/edit$#"

I thought I was messing around somewhere, I found an online sandbox on the Internet for using preg_replace, everything works like clockwork there, but for me, because of the insertion of characters on the sides: "<" and ">", the element that should fit when exiting the line disappears, so even the characters themselves do not even come out. If I remove them or leave spaces between them and the string variable $1, then everything is fine, which is the essence of this joke.
I'm watching a video of one of the PHP Skills participants, it seems like he doesn't have such jokes with these regular expressions.

Answer 1

echo "<xmp>";
var_dump($pattern_regex);
echo "</xmp>";

Answer 2

Everything looks fine, the code is working and outputs what is expected
https://3v4l.org/X3JQA
I think the problem is that you see the results of the code in the browser, and they <id>are processed as an html tag and therefore they are not visible.
In order to verify this, you can open the source code of the page (Ctrl + U) and see if there <id>really is