Req #50809 [Opn->Wfx]: empty(), isset() not helpful - need better alternative

From: Date: Wed, 24 Nov 2010 08:55:47 +0000
Subject: Req #50809 [Opn->Wfx]: empty(), isset() not helpful - need better alternative
References: 1  Groups: php.bugs 
Request: Send a blank email to php-bugs+get-156358@lists.php.net to get a copy of this message
Edit report at http://bugs.php.net/bug.php?id=50809&edit=1

 ID:                 50809
 Updated by:         jani@php.net
 Reported by:        seanr at webolutionary dot com
 Summary:            empty(), isset() not helpful - need better
                     alternative
-Status:             Open
+Status:             Wont fix
 Type:               Feature/Change Request
-Package:            Feature/Change Request
+Package:            *General Issues
 Operating System:   all
 PHP Version:        5.3.2RC1
 Block user comment: N
 Private report:     N

 New Comment:

See the comments.


Previous Comments:
------------------------------------------------------------------------
[2010-01-21 12:28:32] colder@php.net

equivalence is not transitive: var_dump("a" == 0, 0 == "b", "a" ==
"b").

empty is simply awkwardly named. empty($v) is simply equivalent to 
!isset($v) || !$v.

------------------------------------------------------------------------
[2010-01-20 21:47:56] degeberg@php.net

Anything that when cast to boolean is false is regarded as empty.

Seeing as false==0 and 0=="0" then false=="0" because equivalence is
transitive. So if false is empty, then "0" is empty because false=="0".

If you want to check that a string's length is non-zero you can use
strlen().

------------------------------------------------------------------------
[2010-01-20 20:15:02] seanr at webolutionary dot com

Description:
------------
If the value is a string of "0", than it's not a true zero right?  The 
behavior of empty() in this case is utterly absurd.  If you can't fix 
empty, there needs to be a new function to provide a better way to 
test on this than writing our own special functions to work around a 
PHP bug.

$a = 0;
$b = '';
$b = '0'

empty($a) returns true (correctly, but not helpfully)
empty($b) returns true (correctly)
empty($a) returns true (incorrectly, since it actually does have a 
value)

Of course, isset() returns true for all three (correctly, but not 
helpfully).  This means there's no way to find out that $a and $c have 
values I can use and $b doesn't without writing my own special 
function or if statement.  EXTREMELY frustrating.



------------------------------------------------------------------------



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