Doc #65852 [Com]: Wrong documentation about NAN comparison.
| From: | phpmpan at mpan dot pl | Date: | Wed, 09 Oct 2013 09:23:36 +0000 |
| Subject: | Doc #65852 [Com]: Wrong documentation about NAN comparison. | ||
| References: | 1 | Groups: | php.doc.bugs |
| Request: | Send a blank email to doc-bugs+get-10465@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=65852&edit=1
ID: 65852
Comment by: phpmpan at mpan dot pl
Reported by: chalkerx at gmail dot com
Summary: Wrong documentation about NAN comparison.
Status: Open
Type: Documentation Problem
Package: Documentation problem
Operating System: Linux
PHP Version: 5.5.4
Block user comment: N
Private report: N
New Comment:
As documentation states, conversion from NaN to boolean should yield TRUE, and hence TRUE == TRUE
will be TRUE too.
I believe the wording is just not precise and "value" means "numeric value" in
this case. Of course this needs to be fixed.
Previous Comments:
------------------------------------------------------------------------
[2013-10-07 17:48:03] chalkerx at gmail dot com
Whoops, browser-saved title from the old bug.
------------------------------------------------------------------------
[2013-10-07 17:46:00] chalkerx at gmail dot com
Description:
------------
http://www.php.net/manual/en/types.comparisons.php
states:
> Some numeric operations can result in a value represented by the constant NAN. Any loose or
> strict comparisons of this value against any other value, including itself, will have a result of
> FALSE
But that is invalid, because NAN loosely equals to boolean true.
Test script:
---------------
var_dump(sqrt(-1));
var_dump(sqrt(-1) == true);
Expected result:
----------------
As per documentation, the result should be:
double(NAN)
bool(false)
The documentation should be consistent with what actually happens.
Actual result:
--------------
double(NAN)
bool(true)
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Edit this bug report at https://bugs.php.net/bug.php?id=65852&edit=1