When and why should $_REQUEST be used instead of $_GET / $_POST / $_COOKIE?

Question

Question in the title.

And what happens when all 3 of $_GET[foo], $_POST[foo] and $_COOKIE[foo] exist? Which one of them gets

Answer 1

$_REQUEST is only a shortcut to prevent you from testing post, get and cooking if the data can come from any of these.

There are some pitfalls :

• data are taken from GET, POST and finally COOKIE . The last override the first, so be careful with that.
• REST architectures require to separate the POST and GET semantics, you can't rely on $_REQUEST in that case.

Nevertheless, if you know what you're doing, then it's just another handy PHP trick.

I'd use it if I wanted to quickly update a var that may come from several sources. E.G :

• In your controller, to decide what page to serve without checking if the request come from a form action or a hypertext link.

• To check if a session is still active regardless of the way session id are transmitted.