|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Bug #68070 Wrong Answer to a fairly standard calculation
Submitted: 2014-09-22 10:10 UTC Modified: 2014-09-22 10:13 UTC
From: elliot at essentialsystems dot co dot uk Assigned:
Status: Not a bug Package: Math related
PHP Version: Irrelevant OS: Ubuntu
Private report: No CVE-ID: None
View Add Comment Developer Edit
Anyone can comment on a bug. Have a simpler test case? Does it work for you on a different platform? Let us know!
Just going to say 'Me too!'? Don't clutter the database with that please !
Your email address:
Solve the problem:
37 + 18 = ?
Subscribe to this entry?

 [2014-09-22 10:10 UTC] elliot at essentialsystems dot co dot uk
The calculation in the test script should return 34, but yet is returning back 33.999999999998, which is very odd.

Test script:
//expecting 34
var_dump((40120.7 - 36346.0)-3740.7);

Expected result:
Return back of the value of 34.

Actual result:


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2014-09-22 10:13 UTC]
-Status: Open +Status: Not a bug
 [2014-09-22 10:13 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 © 2001-2023 The PHP Group
All rights reserved.
Last updated: Sat Dec 09 09:01:27 2023 UTC