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Bug #51522 function floor
Submitted: 2010-04-10 00:19 UTC Modified: 2010-04-10 00:29 UTC
From: adrianoepn at hotmail dot com Assigned:
Status: Not a bug Package: *General Issues
PHP Version: 5.2.13 OS: windows
Private report: No CVE-ID: None
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 [2010-04-10 00:19 UTC] adrianoepn at hotmail dot com 
Description:
------------
example: 

$value=30.40;
$comision=5;
$val_comision=($value*(1/(1-($comision/100)))-$value);
$suma=$val_comision + $value;
$value_acreditado=floor($suma);

$value_acreditado=31 // wrong  result

but  the  correct answere is 32




Test script:
---------------
example: 

$value=30.40;
$comision=5;
$val_comision=($value*(1/(1-($comision/100)))-$value);
$suma=$val_comision + $value;
$value_acreditado=floor($suma);

$value_acreditado=31 // wrong  result

but  the  correct answere is 32

Expected result:
----------------
 correct answere is 32

Actual result:
--------------
$value_acreditado=31

Patches

patch1 (last revision 2010-04-09 22:26 UTC by adrianoepn at hotmail dot com)

Pull Requests

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 [2010-04-10 00:27 UTC] pajoye@php.net
-Status: Open +Status: Bogus
 [2010-04-10 00:27 UTC] pajoye@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
 
Thank you for your interest in PHP.
 [2010-04-10 00:29 UTC] rasmus@php.net 
And to fix your code, use:

$suma=$val_comision + $value;
$value_acreditado=floor(round($suma,2));
 
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