php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #52016 cast a float variable rounds the value
Submitted: 2010-06-07 16:43 UTC Modified: 2010-06-07 16:47 UTC
From: nbourdial at x-prime dot com Assigned:
Status: Not a bug Package: Scripting Engine problem
PHP Version: 5.2.13 OS: Linux 2.6.26-2-686
Private report: No CVE-ID: None
View Developer Edit
Welcome! If you don't have a Git account, you can't do anything here.
If you reported this bug, you can edit this bug over here.
(description)
Block user comment
Status: Assign to:
Package:
Bug Type:
Summary:
From: nbourdial at x-prime dot com
New email:
PHP Version: OS:

 

 [2010-06-07 16:43 UTC] nbourdial at x-prime dot com 
Description:
------------
Hi,

when I cast a float variable to int, the final value is not correct for some values.

Test script:
---------------
var_dump((int)("37.91"*100));


Expected result:
----------------
int(3791)

Actual result:
--------------
int(3790)

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2010-06-07 16:47 UTC] degeberg@php.net
-Status: Open +Status: Bogus
 [2010-06-07 16:47 UTC] degeberg@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.
 
PHP Copyright © 2001-2025 The PHP Group
All rights reserved. 		Last updated: Fri Dec 05 19:00:01 2025 UTC