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

go to bug id or search bugs for

Bug #74133 PHP function in_array() return wrong.
Submitted: 2017-02-20 06:29 UTC Modified: 2017-02-20 09:57 UTC
From: long dot it dot stu at gmail dot com Assigned:
Status: Not a bug Package: Arrays related
PHP Version: 5.6.30 OS: Centos
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: long dot it dot stu at gmail dot com
New email:
PHP Version: OS:

 

 [2017-02-20 06:29 UTC] long dot it dot stu at gmail dot com 
Description:
------------
---
From manual page: http://www.php.net/security.globals
---
PHP function in_array() return False although it existing.


Test script:
---------------
<?php
$array_1 = range(1, 1.9, 0.1);
var_dump(in_array(1.7, $array_1));
array_2 = range(0, 0.9, 0.1);
var_dump(in_array(0.3, $array_2));
var_dump(in_array(0.6, $array_2));
var_dump(in_array(0.7, $array_2));

//=>it return false;

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2017-02-20 08:20 UTC] requinix@php.net
-Status: Open +Status: Feedback -Package: PHP options/info functions +Package: Arrays related
 [2017-02-20 08:20 UTC] requinix@php.net 
None of those four values exist in either of those two arrays.
 [2017-02-20 09:09 UTC] long dot it dot stu at gmail dot com 
with function range(1, 1.9, 0.1) it return result under:
Array
(
    [0] => 1
    [1] => 1.1
    [2] => 1.2
    [3] => 1.3
    [4] => 1.4
    [5] => 1.5
    [6] => 1.6
    [7] => 1.7
    [8] => 1.8
)
when i check in_array(1.7, range(1, 1.9, 0.1));
it return False;
But all item in array except 1.7 it return False.
in range(0, 0.9, 0.1) it resut too.
 [2017-02-20 09:57 UTC] requinix@php.net
-Status: Feedback +Status: Not a bug
 [2017-02-20 09:57 UTC] requinix@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://www.floating-point-gui.de/

Thank you for your interest in PHP.

Oh, sorry, I mistook how the range() worked.

https://3v4l.org/Nb2iK
The values in the arrays aren't what you think because floating-point numbers aren't always accurate. You could round each value in the array, or use count+array_filter instead, or do something else.
https://3v4l.org/JK901
https://3v4l.org/r8Pq8
https://3v4l.org/dZq7U
 [2017-02-20 11:33 UTC] long dot it dot stu at gmail dot com 
Hi team!. it's clearly. thanks for your feedback!.
 
PHP Copyright © 2001-2025 The PHP Group
All rights reserved. 		Last updated: Sat Oct 25 13:00:01 2025 UTC