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Bug #51838 output problem
Submitted: 2010-05-17 14:11 UTC Modified: 2010-05-17 14:39 UTC
From: dawood at menaitech dot com Assigned:
Status: Not a bug Package: Output Control
PHP Version: 5.2SVN-2010-05-17 (snap) OS: Windows 2003
Private report: No CVE-ID: None
 [2010-05-17 14:11 UTC] dawood at menaitech dot com
Description:
------------
In PHP 5.2.8: 
echo $x=808.163-961.205+153.042 ; 
the result should be 0
but the result was: -2.8421709430404E-14 !!!!!!!!!!!!!


Test script:
---------------
In PHP 5.2.8: 
echo $x=808.163-961.205+153.042 ; 
the result should be 0
but the result was: -2.8421709430404E-14 !!!!!!!!!!!!!



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 [2010-05-17 14:39 UTC] johannes@php.net
-Status: Open +Status: Bogus
 [2010-05-17 14:39 UTC] johannes@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.

.
 
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