PHP / Zend complains about undefined variables.

Question

The situation:

index.php:

<?php
 include("foo.php");
 include("baz.php");
        foo("bar.php");
?>

baz.php:

<?php
    $x = 42;
?>

foo.php:

<?php
    function foo($p) {
     include_once($p); // please dont mind the inclusion hole
    }
?>

bar.php:

<?php
    echo $x;
?>

Zend notice: Undefined variable: x

Placing global $x; in bar.php removes the notice, but I understand why there is a notice about this in the first place.. Doesn't include pretty much work like including C headers? It would mean that the interpreted code would look like this:

<?php
    function foo($p) {
        include_once($p); // please dont mind the inclusion hole
    }
    $x = 42;

    // this however, is included by a function...
    // does the function's scope influence the stuff it includes?
    echo $x; // undefined variable
?>

My editor is the Eclipse/Zend package.

Answer 1

I'm no expert, so please don't flame me if I'm wrong, but I think the file called by include_once or require_once is called in the context of the caller. Since function foo() won't know about $x then neither will any of its called includes. You could experiment by 'declaring' $x inside function foo() with the same setup as above.

Answer 2

I get a bunch of those notices since I'm almost allways goes with "$o .= 'foo'" without any definition. I'm just hiding them with error_reporting(E_ALL ^ E_NOTICE), but I don't know if it's the optimal way in this case.

Answer 3

It doesn't work even if the variable and the function are in the same file.

  1 <?php
  2
  3 $x = 3;
  4
  5 function t()
  6 {
  7   echo $x;
  8 }
  9
 10 t();

Prints nothing.

But add a global

  1 <?php
  2
  3 $x = 3;
  4
  5 function t()
  6 {
  7   global $x;
  8   echo $x;
  9 }
 10
 11 t();

and you can see "3".

In a function you can't see global variables unless you declare it.

Answer 4

yes its the function scope that is causing your issues

if you replace

foo("bar.php");

with

include("bar.php");

you'll see that everything works fine because it puts it into the current scope and not functions scope