PHP Variable Variables

Question

I am writing this comment class:

class Comment {

    public $id;
    public $post_id;
    public $name;
    public $email;
    public $website;
    public $body;
    public $date;
    public $ip_address;
    public $status;

    function __construct($id) {

        global $db;

        $resc = $db->query("SELECT * FROM blog_comments WHERE id='$id' LIMIT 1");

        while($row = $db->fetch_assoc($resc)) {
            while ($comment = current($row)) {
                $key = key($row);
                $this->$key = $comment{$key};
                next($row);
            }
        }
    }
}

Here is what the query inside the constructor will return when run in the database:

query results http://17webshop.com/wp-content/uploads/2009/10/Picture-2.png

But when I run it, this is what print_r(new Comment(1)); spits out:

Comment Object
(
    [id] => 1
    [post_id] => 1
    [name] => J
    [email] => j
    [website] => h
    [body] => b
    [date] => 1
    [ip_address] => :
    [status] => 1
)

Any ideas why I'm only getting the first character of each field?

Thanks.

Were you a Perl programmer, by any chance?

outis
– outis

2009-10-21 21:48:48 +00:00
Commented Oct 21, 2009 at 21:48 — outis
– outis, Commented Oct 21, 2009 at 21:48

Mike B · Accepted Answer · 2009-10-21 22:29:21Z

6

You want

$comment[$key]

$comment{$key} will give you the nth character of a string. Since $key itself is a string, PHP converts that to an integer 0 and you get the first char.

edited Oct 21, 2009 at 22:29

answered Oct 21, 2009 at 21:36

Mike B

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1 Comment

outis Over a year ago

The integer value of those keys is 0, which is also the index of the first character of a string.

timdev · Accepted Answer · 2009-10-21 21:36:10Z

3

current/next is painful, and I'm not sure what's with the {} dereferencing.

Why not just:

$resc = $db->query("SELECT * FROM blog_comments WHERE id='$id' LIMIT 1");

while($row = $db->fetch_assoc($resc)) {
    foreach($row as $key=>$value){
       $this->$key = $value;
    }
}

answered Oct 21, 2009 at 21:36

timdev

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3 Comments

seventeen Over a year ago

you know, i had always wondered what the difference was between [] and {}. Thank you. and yes, this solution is excellent.

timdev Over a year ago

See mike B's answer, which is really a more concise answer. I thought that {} would select a single char, but was too lazy to look it up.

outis Over a year ago

Here's the reference: php.net/manual/en/…

inakiabt · Accepted Answer · 2009-10-21 21:36:29Z

2

I think you need to change this line:

$this->$key = $comment{$key};

with:

$this->$key = $comment[$key];

answered Oct 21, 2009 at 21:36

inakiabt

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