|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Bug #44311 Bug in arithmetic operation: 173.42-173.42=2.8421709430404E-014
Submitted: 2008-03-02 13:25 UTC Modified: 2008-03-02 15:04 UTC
From: sawas at poczta dot onet dot pl Assigned:
Status: Not a bug Package: Math related
PHP Version: 4.4.8 OS: WinXP, Debian
Private report: No CVE-ID: None
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If this is not your bug, you can add a comment by following this link.
If this is your bug, but you forgot your password, you can retrieve your password here.
Bug Type:
From: sawas at poczta dot onet dot pl
New email:
PHP Version: OS:


 [2008-03-02 13:25 UTC] sawas at poczta dot onet dot pl
I found a bug in arithmetic operation.
Simple subtraction of amounts gives inaccurate result.

Reproduce code:
$a = 160.00 + 5.90 + 7.52;
$b = 173.42;
print $a-$b;

Expected result:

Actual result:


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2008-03-02 15:04 UTC]
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:
Thank you for your interest in PHP.

PHP Copyright © 2001-2024 The PHP Group
All rights reserved.
Last updated: Sat Jul 20 12:01:28 2024 UTC