On maandag 15 december 2003 10:24 Gerard Samuel told the butterflies:
> Just curious about something I came across.
> I was looking at the $GLOBAL array, to see what my script was leaving
> behind. $GLOBALS contains a reference to itself.
> Even though its a reference, whats the sense with that??
> Once its global, why should it have to call on itself?
> Im currently running php 4.3.4 on FreeBSD 4.9
>
> Thanks
>
> A script to try out ->
> <?php
>
> header('content-type: text/plain');
>
> var_dump(isset($GLOBALS['GLOBALS']['GLOBALS'])); // returns true
>
> // Prints out the $GLOBALS array
> // including one reference to itself
> // then starts another but quits with *RECURSION* var_dump($GLOBALS);
>
> >
Well .. it basically just "Contains a reference to every variable which is
currently available within the global scope of the script. The keys of this
array are the names of the global variables.". Since $GLOBALS itself is
global, that too is contained.
So:
var_dump(isset($GLOBALS['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS
']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBAL
S']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBA
LS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOB
ALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLO
BALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GL
OBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['G
LOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['
GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'][
'GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']
['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'
]['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS
']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBAL
S']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBA
LS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOB
ALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLO
BALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GL
OBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['G
LOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['
GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'][
'GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']
['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'
]['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS
']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBAL
S']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBA
LS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOB
ALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLO
BALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GL
OBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['G
LOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['
GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'][
'GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']
['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS']['GLOBALS'
]));
Will still print out true. the displaying of *RECURSION* is to prevent, well
.. ehmm, recursively printing out the $GLOBALS array over and over again.
This is something new in PHP 4.0.4. Read the manual on page
http://nl3.php.net/manual/en/function.print-r.php:
Note: Prior to PHP 4.0.4, print_r() will continue forever if given
an array or object that contains a direct or indirect reference to itself.
An example is print_r($GLOBALS) because $GLOBALS is itself a global variable
that contains a reference to itself.
:),
Wouter
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
