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Date: Wed, 23 Nov 2011 14:42:41 -0000
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Subject: Re: [PHP-DEV] 5.4 regression: non-existent sub-sub keys now have
 values
From: glopes@nebm.ist.utl.pt ("Gustavo Lopes")

Em Wed, 23 Nov 2011 14:19:42 -0000, Ferenc Kovacs <tyra3l@gmail.com>  
escreveu:

> On Wed, Nov 23, 2011 at 3:14 PM, Daniel Convissor <
> danielc@analysisandsolutions.com> wrote:
>
>> > It's actually very simple. Take variable $a which is a string
>> > ("foo"). Now it you do $a[0] that would produce first letter - "f".
>> > Now here's a tricky part - if you do $a['blah'] it would convert
>> > 'blah' to number, get 0 and return the same letter "f".
>>
>> To me, this is the bug.  $a['blah'] does not exist.  An undefined index
>> notice should be raised.  The key "blah" should not be converted to 0.
>> The following two things should behave the same:
>>
>> $b = array('exists' => 'foo');
>> echo $b['blah'] . "\n";
>>
>> $a = 'foo';
>> echo $a['blah'] . "\n";
>>
>> But that second one echos out "f".  This is a huge WTF.
>
>
> and the following should also behave the same:
> $a = 'foo';
>
> echo $a[2];
> echo $a['2'];
> echo $a['2 cats'];
>
> because this is how the type juggling works in php:
> http://php.net/manual/en/language.types.type-juggling.php
>

But this is *not* (and afaik has never been) how indexes in arrays work.  
The conversion of array keys has always different rules:

<?php
$a['2 cats'] = null;
var_dump($a);
^D
array(1) {
   ["2 cats"]=>
   NULL
}

The mapping between strings and integers used for arrays is 1 to 1, and  
strings that can be mapped to integers are always mapped (so you cannot  
have a '1' (string) key and a 1 (int) key). These different rules are what  
makes possible to store any kind of string in an array, and changing this  
would be a huge error.

I see, however, that it's not the case for indexing strings, where the lax  
rules are followed:

<?php
$a = 'foo';
var_dump($a['2 cats']);
^D
string(1) "o"

If there's any change to be made, it would be to change the way string  
indexing works, not the other way around.

-- 
Gustavo Lopes