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Bug #73864 '3.' is considered as a numeric string
Submitted: 2017-01-04 21:44 UTC Modified: 2017-01-06 17:51 UTC
From: mumu at seznam dot cz Assigned: cmb (profile)
Status: Not a bug Package: Scripting Engine problem
PHP Version: 7.1.0 OS: Windows 10
Private report: No CVE-ID: None
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 [2017-01-04 21:44 UTC] mumu at seznam dot cz 
Description:
------------
'3.' is evaluated as a numeric string even it is not a valid number.

Test script:
---------------
<?php

echo '3. ' . (is_numeric('3.') ? 'IS' : 'IS NOT') . ' numeric';

?>

Expected result:
----------------
is_numeric('3.') returns false.

Actual result:
--------------
is_numeric('3.') returns true.

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 [2017-01-04 21:48 UTC] requinix@php.net
-Status: Open +Status: Feedback
 [2017-01-04 21:48 UTC] requinix@php.net 
It is a valid number. Why shouldn't it be?
 [2017-01-06 10:43 UTC] mumu at seznam dot cz
-Status: Feedback +Status: Open
 [2017-01-06 10:43 UTC] mumu at seznam dot cz 
I would not expect 3. to be a valid syntax of a number. However, it seems to be valid notation in PHP. Personally, I would be happy if this syntax is not a valid number as it is quite confusing and weird (has no match in real world).
 [2017-01-06 17:51 UTC] cmb@php.net
-Status: Open +Status: Not a bug -Package: Unknown/Other Function +Package: Scripting Engine problem -Assigned To: +Assigned To: cmb
 [2017-01-06 17:51 UTC] cmb@php.net 
> (has no match in real world)

Well, floating point numbers generally do not match the real
world. Anyhow, the valid syntax of float numbers is well
documented[1], so this is not a bug.

[1] <http://php.net/manual/en/language.types.float.php>
 [2017-01-07 06:38 UTC] a at b dot c dot de 
A real-world example of "3." results from measuring the circumference and diameter of a circle to one significant digit and taking their ratio (cf. I Kings 7:23).
 
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