how to change all input field values into upper case

Question

I have set of PHP fields.

Before sending the values into a query, I want to change the letters to upper case.

Is there a way to do something like:

Answer 1

$_POST = array_map("strtoupper", $_POST);

This will make all values in the POSTed form upper case.

There is no general method to apply a function to all variables in scope. They need to be in an array first.