I am trying to get the id from the URL.
URL : http://localhost/user_notes/user.php?id=1234
echo $_GET['id']; // outputs 1234
But If I use # at the start of the id then I am not getting id.
URL : http://localhost/user_notes/user.php?id=#1234
echo $_GET['id']; // outputs nothing
If you want to use # as some value in url, you need to use url encoded version of # i.e %23, because # signifies an internal link to some section of the page. See https://www.yourhtmlsource.com/text/internallinks.html & https://way2tutorial.com/html/html_internal_links.php
If your url is http://localhost/user_notes/user.php?id=%231234, then you'll get # in
echo $_GET['id'];