What's wrong with using $_REQUEST[]?

Question

I\'ve seen a number of posts on here saying not to use the $_REQUEST variable. I usually don\'t, but sometimes it\'s convenient. What\'s wrong with it?

Answer 1

GET requests should be idempotent and POST requests are generally not. This means that data in $_GET and $_POST should generally be used in different ways.

If your application is using data from $_REQUEST, it will behave the same for both GET and POST requests, which violates the idempotence of GET.