How to read the query string in PHP and HTML?

Question

a URL ending with something like portal.php?key2=hello how can I get the value of "key2"?

Answer 1

$_GET['key2']

will get you the value from a query string.

$_POST['key2']

will get you the value from a form posted.

$_REQUEST['key2']

will get you either of the above if it exists.