Edit report at https://bugs.php.net/bug.php?id=60039&edit=1
ID: 60039
Comment by: ni...@php.net
Reported by: ni...@php.net
Summary: array_key_exists behaves different from isset for
float keys
Status: Open
Type: Feature/Change Request
Package: Arrays related
PHP Version: 5.4.0beta1
Block user comment: N
Private report: N
New Comment:
@Artefacto Yes, I know that it isn't perfectly obvious that the behavior should
match. But I'll try to explain why I think so:
a) From the user perspective: What would be a typical application of
array_key_exists? Probably it's checking whether a key exists before using it:
if (array_key_exists($key, $array)) {
$array[$key];
}
What would you expect from this code? I would expect that the if is evaluated
for every key that $array[$key] won't throw an "Undefined index" notice for.
For example (why I actually opened the bug) Twig does array_key_exists checks
when accessing array offsets and people have reported bugs about it throwing
errors when used with have whole-number float arguments (like 14.0).
b) From the PHP perspective: It's arguable whether in [4 => "hhh"] the key 4.1
exists or not. I mean, you can access [4 => "hhh"][4.1], so in some way it does
exist.
c) We have a precedent: array_key_exists was already modified in the past to
support NULL arguments just like isset() does. I don't see why we can't do that
for the other argument types.
Previous Comments:
------------------------------------------------------------------------
[2011-10-11 19:14:10] cataphr...@php.net
It's very arguable whether the behavior of the two should match.
A argument for the current behavior would go like this: in $a = [4 => "hhh"],
the key 4.5 doesn't exist, so key_exists should return false; on the other hand
$a[4.5] exists and is not null, so isset should return true. There are some
problems with this argument, namely that key_exists actually rejects the
arguments (it sends a warning) and that there is a very slight mismatch between
isset and array dereferencing, but it's just to show this is not a bug
(violation of well established specifications), but instead a feature request
that merits more discussion.
------------------------------------------------------------------------
[2011-10-11 12:19:09] ni...@php.net
The following patch has been added/updated:
Patch Name: array_key_exists_patch.txt
Revision: 1318335549
URL:
https://bugs.php.net/patch-display.php?bug=60039&patch=array_key_exists_patch.txt&revision=1318335549
------------------------------------------------------------------------
[2011-10-11 12:18:40] ni...@php.net
Description:
------------
array_key_exists allows only string, int and null keys. For everything else
it'll throw an error.
isset on the other hand allows floats, resources and bools too. floats are cast
to int and resources and bools are handled as ints.
array_key_exists behavior should match isset behavior.
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Edit this bug report at https://bugs.php.net/bug.php?id=60039&edit=1
