I have the following:
preg_replace('/\B@[^\B ]+/', '<a href="profile.php">$0</a>');
Which checks for any string that starts with @ and ends with a space and turns it into a link.
Now what I need is to create another preg_replace that would remove the @ symbol from the string, like @hello, so that it would just become hello.
I need this so that I can change the link in the first preg_replace to become <a href="profile.php?user=hello>$0</a>.
You can wrap part of your patern in () to create new variable In this case you will have your match string without @ under $1 variable
preg_replace('/\B@([^\B ]+)/', '<a href="profile.php?profile=$1">$0</a>');