NYCPHP Meetup

[DeWitt, Michael]

Dan,

Thank you very much for figuring this one out.  

It is clear to me now that one cannot extend the elements (structure?) of an
array by merely adding on a new element syntactically where elements already
have values. 

I think I was not really following what was going on because of PHP's array
handling flexibility like in this example:

$a=array();
$a['1']['2']['3']='the';
$a['2']['2']['3']['4']=' answer';

echo $a['1']['2']['3'];
echo $a['2']['2']['3']['4'];

Outputs:

the answer

Call me crazy, but I tend to build associative arrays on the fly and haven't
run into this issue until now, so this was of real interest to me. 

Mike

> -----Original Message-----
> From:	Dan Cech [SMTP:dcech at phpwerx.net]
> Sent:	Thursday, February 12, 2004 12:59 PM
> To:	NYPHP Talk
> Subject:	Re: [nycphp-talk] Array handling - Why does this happen?
> 
> It's not immediately clear what's going on in the code you presented, 
> but I have extracted the relevant code, which is:
> 
> $answer = array (
>    'Yes' => array (
>      'Yes' => 'Yes',
>      'count' => 0
>    ),
>    'No' => array (
>      'No' => 'No',
>      'count' => 0
>    )
> );
> 
> $val='Yes';
> $val1='No';
> 
> $answer[$val]['count']=8888;
> echo $answer[$val]['count']."<br>";
> 
> $answer[$val1]['count']=9999;
> echo $answer[$val1]['count']."<br>";
> 
> $answer = array (
>    'Yes' => 'Yes',
>    'No' => 'No'
> );
> 
> $val='Yes';
> $val1='No';
> 
> $answer[$val]['count']=8888;
> echo $answer[$val]['count']."<br>";
> 
> $answer[$val1]['count']=9999;
> echo $answer[$val1]['count']."<br>";
> 
> As you can see, in the first case $answer[$val] is an array, whereas in 
> the second case $answer[$val] is a string.
> 
> What's happening I think is that you are unwittingly invoking the 
> (deprecated) syntax for accessing a string by character:
> 
> $mystring = 'hello';
> 
> echo $mystring{0};
> echo $mystring[0];
> 
> both should result in 'h';
> 
> This syntax can also be used to assign into a string...which is what is 
> happening here.
> 
> The 'count' is being to converted to the integer 0, and the first 
> character in the string is being overwritten with the first character 
> from the value you are assigning.
> 
> So in the second example:
> 
> $answer[$val] is 'Yes'
> 
> Then we do:
> 
> $answer[$val]['count'] = 8888;
> 
> which is equivalent to:
> 
> $answer[$val]{0} = 8888;
> 
> so $answer[$val] is now '8es'
> 
> then we do:
> 
> echo $answer[$val]['count'];
> 
> which is equivalent to:
> 
> echo $answer[$val]{0};
> 
> which results in '8'
> 
> An interesting little problem for sure.
> 
> Dan
>