Edit report at https://bugs.php.net/bug.php?id=45712&edit=1
ID: 45712
Comment by: cmbecker69 at gmx dot de
Reported by: for-bugs at hnw dot jp
Summary: $something == NaN returns true with 5.3, false with
5.2.*
Status: Re-Opened
Type: Bug
Package: Variables related
Operating System: *
PHP Version: 5.2CVS, 5.3CVS, 6CVS (2008-08-05)
Assigned To: tony2001
Block user comment: N
Private report: N
New Comment:
> Please explain.
It seems there was a bug *before* PHP 5.4, because if $a === $b,
then $a == $b by definition.
Previous Comments:
------------------------------------------------------------------------
[2011-05-26 07:59:24] [email protected]
Reopening because the associated test tests INF as well. However, this is about
INF:
// 5.3.7-dev (and all past PHP versions, afaict)
$inf = pow(0,-2); var_dump($inf==$inf); var_dump($inf===$inf); // false true
// 5.4.0-dev
$inf = pow(0,-2); var_dump($inf==$inf); var_dump($inf===$inf); // true true
Please explain.
And @jwvdveer, it was indeed fixed (in 5.3) and made to return false.
------------------------------------------------------------------------
[2010-07-28 01:28:53] jwvdveer at gmail dot com
Please, reopen this bug. It's not working in PHP 5.3.3 on Windows platform
(released at 2010-07-21).
The behaviour of a comparison to NAN is the same as noted here.
It's not just a `me too`, but this thread shouln't have been closed.
------------------------------------------------------------------------
[2008-08-07 08:36:33] [email protected]
This bug has been fixed in CVS.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
------------------------------------------------------------------------
[2008-08-07 07:37:04] [email protected]
I'm testing a patch for it.
------------------------------------------------------------------------
[2008-08-05 12:52:06] for-bugs at hnw dot jp
NaN is not exact number. So, NaN should not equals itself. Additionaly, NaN ==
NaN is false in C. You can see behavior of C as follows.
$ cat nan.c
int main() {double d;d=(-1e300*1e300)/(1e300*1e300);if (d==d) return 1; else
return 2;}
$ gcc nan.c; ./a.out; echo $?
2
$
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