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Bug #74347 -1 - 0.1 + 1 + 0.1 bugg
Submitted: 2017-03-31 09:17 UTC Modified: 2017-03-31 09:18 UTC
From: stefan at van-echtelt dot nl Assigned:
Status: Not a bug Package: Output Control
PHP Version: Irrelevant OS: Windows
Private report: No CVE-ID: None
View Developer Edit
 [2017-03-31 09:17 UTC] stefan at van-echtelt dot nl 
Description:
------------
$test = -1 - 0.1 + 1 + 0.1;
print $test;

if you print this in php the value will be -8.3266726846887E-17.
It should be 0.

Test script:
---------------
$test = -1 - 0.1 + 1 + 0.1;
print $test;

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 [2017-03-31 09:18 UTC] requinix@php.net
-Status: Open +Status: Not a bug
 [2017-03-31 09:18 UTC] requinix@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://www.floating-point-gui.de/

Thank you for your interest in PHP.
 
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