Hashtag preg_replace

Question

I have a web app which is creating and linking to #hashtags and I have noticed that if someone creates a #hashtag of #JB22 that the following code breaks.

Is there away in the regex I can allow numbers at the end of a #hashtag

$users = preg_replace("~(<var data-type=\"user\" class=\"userHighlight\" id=\"(.*?)\">)(.*?)(</var>)~", "<_link>$2|$3</_link> ", $start);
$tags = preg_replace("~(<var data-type=\"tag\" class=\"tagHighlight\" id=\"(.*?)\">)#(.*?)(</var>)~", "<_link>tag://$3|#$3</_link> ", $users);
$last = preg_replace("~(^|\\s)#(\\w*[a-zA-Z_]+\\w*)~", " <_link>tag://$2|#$2</_link> ", $tags);

Answer 1

Replace this [a-zA-Z_]+ with [a-zA-Z_0-9]+ or if you want the numbers only at the end of the pattern you can use ([a-zA-Z_]+?[a-zA-Z_0-9]+?).