I use a query string, for example test.php?var=1.
test.php?var=1
How can I check if a user types anything after that, like another string...
I try to redirect
I'm not sure I fully understand what you want, but if you're not interested in the positioning of the parameters this should work:
if ( isset($_GET['var']) && count($_GET) > 1 ) { //do something if var and another parameter is given }