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Doc Bug #31927 in_array() not working with array containing strings as needle
Submitted: 2005-02-11 05:53 UTC Modified: 2005-02-13 21:26 UTC
From: bart at mediawave dot nl Assigned:
Status: Not a bug Package: Documentation problem
PHP Version: 5CVS-2005-02-11 (dev) OS: WinXP
Private report: No CVE-ID: None
View Developer Edit
 [2005-02-11 05:53 UTC] bart at mediawave dot nl 
Description:
------------
in_array() doesn't work with an array containing strings (larger then one character) as a needle.

Reproduce code:
---------------
<?php

$a = array(array("Mac", "NT"), array("Irix", "Linux"), "OS2");

if (in_array(array("NT", "Linux"), $a)) {
   echo "NT Linux found\n";
}

if (in_array(array("XP", "Unix"), $a)) {
   echo "XP Unix found\n";
}

if (in_array("OS2", $a)) {
   echo "OS2 found\n";
}

?> 

Expected result:
----------------
NT Linux found
OS2 found

Actual result:
--------------
OS2 found

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 [2005-02-11 20:52 UTC] tony2001@php.net 
No bug here: in_array() looks for exact match.

This code works fine:
<?php
$a = array(array("NT", "Linux"), array("Irix", "Linux"), "OS2");

if (in_array(array("NT", "Linux"), $a)) {
   echo "NT Linux found\n";
}

?>
 [2005-02-12 01:16 UTC] bart at mediawave dot nl 
The documentation clearly states:

in_array -- Checks if a "value" exists in an array

It doesn't say:

in_array -- Checks if a "variable" exists in an array

An array itself isn't a value. It's a variable containing a collection of values. So, one would expect that in_array checks if all these "values" exist in the haystack. (Regardless of the containing variable type/structure) It shouldn't check if a variable exists in the haystack. 

The exact match behaviour in your example should only happen when the parameter strict is set. (In my opinion at least)
 [2005-02-12 14:45 UTC] tony2001@php.net 
>An array itself isn't a value. 
Nope. Don't know who told you this, but he/she was definitely wrong.

>So, one would expect that in_array checks if all these
>"values" exist in the haystack.
No, see examples in the docs. 

No bug here.
 [2005-02-12 22:22 UTC] bart at mediawave dot nl 
You are right. It isn't a bug. in_array was apparently designed to work this way and does so properly.

Maybe we should change this to a change/feature request then? Or otherwise a documentation problem? It simply isn't intuitive for people now.

This is my last attempt. I won't be re-opening this bug anymore.
 [2005-02-12 22:32 UTC] tony2001@php.net 
Well, probably this should be clarified in the docs.
But the current description looks rather clear to me, though.
Reclassifying as docu problem.
 [2005-02-13 21:26 UTC] vrana@php.net 
No bug here.
 
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