Bug #72487 [Opn->Nab]: 100 - 99.6 why result = 0.400000001

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Newsgroups php.standards
Message-ID <[email protected]>
Edit report at https://bugs.php.net/bug.php?id=72487&edit=1

 ID:                 72487
 Updated by:         [email protected]
 Reported by:        wee_weerapat at hotmail dot com
 Summary:            100 - 99.6 why result = 0.400000001
-Status:             Open
+Status:             Not a bug
 Type:               Bug
 Package:            PHP Language Specification
 Operating System:   Mac & Windows
 PHP Version:        5.5.37
 Block user comment: N
 Private report:     N

 New Comment:

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.

.


Previous Comments:
------------------------------------------------------------------------
[2016-06-24 11:37:27] wee_weerapat at hotmail dot com

Description:
------------
I'm not sure. 100-99.6 the result will return 0.400000001
and i try many case 100 - 99.96 the result still same 0.040000000000006
There return another position of number

Test script:
---------------
echo 100-99.6;
echo "<br>";
echo 100-99.96;
echo "<br>";
echo 1000-999.96;

Expected result:
----------------
0.4
0.04
0.04

Actual result:
--------------
0.40000000000001
0.040000000000006
0.039999999999964


------------------------------------------------------------------------



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