Access a global variable in a PHP function

Question

According to the most programming languages scope rules, I can access variables that are defined outside of functions inside them, but why doesn't this code work?

<?php     $data = 'My data';      function menugen() {         echo "[" . $data . "]";     }      menugen(); ?> 

The output is [].

Answer 1

It is not working because you have to declare which global variables you'll be accessing:

$data = 'My data';  function menugen() {     global $data; // <-- Add this line      echo "[" . $data . "]"; }  menugen(); 

Otherwise you can access it as $GLOBALS['data']. See Variable scope.

Even if a little off-topic, I'd suggest you avoid using globals at all and prefer passing as parameters.