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Bug #49747 floor() issue
Submitted: 2009-10-02 10:27 UTC Modified: 2009-10-02 11:30 UTC
From: rajiv dot ambegaokar at oracle dot com Assigned:
Status: Not a bug Package: Math related
PHP Version: 5.2.11 OS: Windows XP
Private report: No CVE-ID: None
View Developer Edit
 [2009-10-02 10:27 UTC] rajiv dot ambegaokar at oracle dot com 
Description:
------------
Floor function not working properly.

Reproduce code:
---------------
<?php
$a = 43.1234 ;
$a = floor($a * 10000);
echo $a;
 ?>

Expected result:
----------------
431234

Actual result:
--------------
431233

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 [2009-10-02 11:30 UTC] sjoerd@php.net 
Floating point values have a limited precision. Hence a value might 
not have the same string representation after any processing. That also
includes writing a floating point value in your script and directly 
printing it without any mathematical operations.

If you would like to know more about "floats" and what IEEE
754 is, read this:
http://docs.sun.com/source/806-3568/ncg_goldberg.html
 
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