[PHP-BUG] Req #60944 [NEW]: Unable to detect if variable exists vs. is null

[lampacz+php at gmail dot com]

From: 
Operating system: Linux
PHP version:  5.3.9
Package:  Variables related
Bug Type: Feature/Change Request
Bug description:Unable to detect if variable exists vs. is null

Description:

There is no difference between $x = NULL and unset($a). So i'm unable to
detect if variable was defined (so it can be defined and be filled with
null)

http://www.php.net/manual/en/types.comparisons.php Table Comparisons of $x
with PHP functions, rows 2 - 4 gives same results


Expected result:

Different results for undefined variables and null variables


-- 
Edit bug report at https://bugs.php.net/bug.php?id=60944&edit=1
-- 
Try a snapshot (PHP 5.4):
https://bugs.php.net/fix.php?id=60944&r=trysnapshot54
Try a snapshot (PHP 5.3):
https://bugs.php.net/fix.php?id=60944&r=trysnapshot53
Try a snapshot (trunk):  
https://bugs.php.net/fix.php?id=60944&r=trysnapshottrunk
Fixed in SVN:
https://bugs.php.net/fix.php?id=60944&r=fixed
Fixed in SVN and need be documented: 
https://bugs.php.net/fix.php?id=60944&r=needdocs
Fixed in release:
https://bugs.php.net/fix.php?id=60944&r=alreadyfixed
Need backtrace:  
https://bugs.php.net/fix.php?id=60944&r=needtrace
Need Reproduce Script:   
https://bugs.php.net/fix.php?id=60944&r=needscript
Try newer version:   
https://bugs.php.net/fix.php?id=60944&r=oldversion
Not developer issue: 
https://bugs.php.net/fix.php?id=60944&r=support
Expected behavior:   
https://bugs.php.net/fix.php?id=60944&r=notwrong
Not enough info: 
https://bugs.php.net/fix.php?id=60944&r=notenoughinfo
Submitted twice: 
https://bugs.php.net/fix.php?id=60944&r=submittedtwice
register_globals:
https://bugs.php.net/fix.php?id=60944&r=globals
PHP 4 support discontinued:  
https://bugs.php.net/fix.php?id=60944&r=php4
Daylight Savings:https://bugs.php.net/fix.php?id=60944&r=dst
IIS Stability:   
https://bugs.php.net/fix.php?id=60944&r=isapi
Install GNU Sed: 
https://bugs.php.net/fix.php?id=60944&r=gnused
Floating point limitations:  
https://bugs.php.net/fix.php?id=60944&r=float
No Zend Extensions:  
https://bugs.php.net/fix.php?id=60944&r=nozend
MySQL Configuration Error:   
https://bugs.php.net/fix.php?id=60944&r=mysqlcfg

Req #60944 [Com]: Unable to detect if variable exists vs. is null

[lampacz+php at gmail dot com]

Edit report at https://bugs.php.net/bug.php?id=60944&edit=1

 ID: 60944
 Comment by: lampacz+php at gmail dot com
 Reported by:lampacz+php at gmail dot com
 Summary:Unable to detect if variable exists vs. is null
 Status: Open
 Type:   Feature/Change Request
 Package:Variables related
 Operating System:   Linux
 PHP Version:5.3.9
 Block user comment: N
 Private report: N

 New Comment:

Marvelous.

Sugestion for new function: is_defined(mixed $var)

which internally return array_key_exists($var, get_defined_vars()); ?

Thank you for.


Previous Comments:

[2012-02-01 09:54:15] larue...@php.net




[2012-02-01 08:05:10] lampacz+php at gmail dot com

Description:

There is no difference between $x = NULL and unset($a). So i'm unable to detect 
if variable was defined (so it can be defined and be filled with null)

http://www.php.net/manual/en/types.comparisons.php Table Comparisons of $x with 
PHP functions, rows 2 - 4 gives same results


Expected result:

Different results for undefined variables and null variables







-- 
Edit this bug report at https://bugs.php.net/bug.php?id=60944&edit=1