|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Bug #34246 Dividing number by half over and over eventually returns 0
Submitted: 2005-08-25 11:41 UTC Modified: 2005-08-25 11:48 UTC
From: platinumsupreme at aol dot com Assigned:
Status: Not a bug Package: Math related
PHP Version: 4.4.0 OS: Windows XP
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: platinumsupreme at aol dot com
New email:
PHP Version: OS:


 [2005-08-25 11:41 UTC] platinumsupreme at aol dot com
There is a problem out there that states that if you take a number and keep dividing it by half you should never reach zero. But apparently in PHP that is not the case..


Reproduce code:
$number = 50;
echo "Starting Number: $number<br>";

while($number > 0){
$number = $number / 2;
echo "Number: $number<br>";

Expected result:
It should just go on for a ridiculous amount of time until it memory leaks...

Actual result:
It ends up at 0.


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2005-08-25 11:48 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: Fri Jun 02 04:03:38 2023 UTC