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Bug #48846 convertin int to float
Submitted: 2009-07-08 06:52 UTC Modified: 2009-07-08 20:35 UTC
From: marcin at datamomentu dot eu Assigned:
Status: Not a bug Package: Variables related
PHP Version: 5.3.0 OS: Windows XP
Private report: No CVE-ID: None
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From: marcin at datamomentu dot eu
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 [2009-07-08 06:52 UTC] marcin at datamomentu dot eu 
Description:
------------
$t1 = floatval(8.95);
		var_dump($t1);
		$t2 = $t1*100;
		var_dump($t2);
		$t3 = (int)$t2;
		var_dump($t3);
		
t3 should be 8.95 and its 8.94

its true for t1 = 7.95 or 9.95 

its not true for t1 = 6.95 or 5.95 or 4.95 etc 



Reproduce code:
---------------
$t1 = floatval(8.95);
var_dump($t1);
t2 = $t1*100;
var_dump($t2);
$t3 = (int)$t2;
var_dump($t3);

Expected result:
----------------
t3 = 8.95

Actual result:
--------------
t3 = 8.94

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 [2009-07-08 20:35 UTC] jani@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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