From:
Operating system: Windows/Linux
PHP version: 5.3.10
Package: Math related
Bug Type: Bug
Bug description:string math with vast differential numbers yield invalid math.
Description:
------------
Tried this on the latest 5.3.10 and also on 5.2.17
It is a bit difficult to put into words, but math with varying
string-number
sizes calculates wrong.
Simply put:
THIS IS CORRECT:
-----------------
$x = 20.22
: double = 20.22
$y = ("10.10" + "10.12");
: double = 20.22
$x == $y
: bool = TRUE
THIS IS BUGGED:
-------------------
$x = 20.22
: double = 20.22
$y = ("19.10" + "1.12"); //20.22
: double = 20.22
$x == $y
: bool = FALSE
For some reason, if you have a wide number spread in the string math, the
boolean fails, even though they are both shown as float/double numbers
The simple fix is to wrap round() around the string math. Can't really
explain
it.
Test script:
---------------
<?php
$x = 23.36;
$y = ("21.42" + "1.94");
if ($x < $y) {
echo "math fail<br/>";
} else {
echo "math win<br/>";
}
var_dump($x, $y);
echo "<br/>";
$x = 23.36;
$y = ("10.36" + "13.00");
if ($x < $y) {
echo "math fail<br/>";
} else {
echo "math win<br/>";
}
var_dump($x, $y);
?>
Expected result:
----------------
I expect to see:
math win
float(23.36) float(23.36)
math win
float(23.36) float(23.36)
Actual result:
--------------
What I really see is:
math fail
float(23.36) float(23.36)
math win
float(23.36) float(23.36)
--
Edit bug report at https://bugs.php.net/bug.php?id=61108&edit=1
--
Try a snapshot (PHP 5.4):
https://bugs.php.net/fix.php?id=61108&r=trysnapshot54
Try a snapshot (PHP 5.3):
https://bugs.php.net/fix.php?id=61108&r=trysnapshot53
Try a snapshot (trunk):
https://bugs.php.net/fix.php?id=61108&r=trysnapshottrunk
Fixed in SVN:
https://bugs.php.net/fix.php?id=61108&r=fixed
Fixed in SVN and need be documented:
https://bugs.php.net/fix.php?id=61108&r=needdocs
Fixed in release:
https://bugs.php.net/fix.php?id=61108&r=alreadyfixed
Need backtrace:
https://bugs.php.net/fix.php?id=61108&r=needtrace
Need Reproduce Script:
https://bugs.php.net/fix.php?id=61108&r=needscript
Try newer version:
https://bugs.php.net/fix.php?id=61108&r=oldversion
Not developer issue:
https://bugs.php.net/fix.php?id=61108&r=support
Expected behavior:
https://bugs.php.net/fix.php?id=61108&r=notwrong
Not enough info:
https://bugs.php.net/fix.php?id=61108&r=notenoughinfo
Submitted twice:
https://bugs.php.net/fix.php?id=61108&r=submittedtwice
register_globals:
https://bugs.php.net/fix.php?id=61108&r=globals
PHP 4 support discontinued:
https://bugs.php.net/fix.php?id=61108&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=61108&r=dst
IIS Stability:
https://bugs.php.net/fix.php?id=61108&r=isapi
Install GNU Sed:
https://bugs.php.net/fix.php?id=61108&r=gnused
Floating point limitations:
https://bugs.php.net/fix.php?id=61108&r=float
No Zend Extensions:
https://bugs.php.net/fix.php?id=61108&r=nozend
MySQL Configuration Error:
https://bugs.php.net/fix.php?id=61108&r=mysqlcfg
