Question about array_merge

thedahm

This code:

$_SESSION["signup"] = array_merge($_SESSION["signup"], $_POST);

Produces this warning:

"Warning: array_merge() [function.array-merge]: Argument #1 is not an array in ...."

Which in the end, none of the form data seems to get stored to $_SESSION["signup"] variable.

I'm about as newb to php as newb can be, and this is a site that I have inherited responsibilities for, not something I wrote. I know that the scripts were written for and used with PHP4, but my server (iis5) is currently using PHP5. I'm hoping that there is quick and simple answer to this, but I think I probably just need a better understanding of the $_SESSION variable.

Any insight, fix or link to point me in the right direction on what to read will be greatly appreciated. 🙂

Houdini

Did you use session_start)_ before you tried to access that session variable, and what version of PHP are you using, with the limited information it is hard to really help you much more?

thedahm

I'm using PHP 5.1.2 on a Win2k machine running IIS5.

In the php.ini file, I have set the option "session.auto_start = 1" ... so from what I understand according to http://us2.php.net/manual/en/ref.session.php:

"When a visitor accesses your site, PHP will check automatically (if session.auto_start is set to 1) or on your request (explicitly through session_start() or implicitly through session_register()) whether a specific session id has been sent with the request. If this is the case, the prior saved environment is recreated."

I should not need to explicitly call session_start(), or is that not a safe assumption?

Sorry if I've not provided enough information to go on. It's this specific line of code and the warning that I want to understand, so unless something else is needed, I'm refraining from posting the rest of the code ... mostly to keep my thinking on this focused, but I figure any additional information that you need will probably be helpful for me in learning what this particular code is dependent on as well. 🙂

Installer

Is that or any other $SESSION element available to you otherwise? For example, what's the output of "print_r($SESSION);"?

thedahm

It would appear so.

print_r($_SESSION); // following the line of code in question

outputs:
Array ( [logged_in] => [signup] => )

I haven't noticed any problems anywhere else on the site where references to $_SESSION are made.

Installer

That looks like the problem; $_SESSION['signup'] isn't an array, just like the error message says. To force it to work, you could use the method described in the "Warning" box here. Maybe not ideal, but it should work.

thedahm

That seems to work, thank you. 🙂

What would be the ideal way to create and initialize an array named "signup" to the session?

Installer

It works like any other array. For example, if you had post data $POST['height'] and $POST['weight'] and wanted to form $SESSION['signup'] to comprise them, you could do:

$_SESSION['signup']['height'] = $_POST['height'];
$_SESSION['signup']['weight'] = $_POST['weight'];

Or, you could populate it directly:

$_SESSION['signup']['height'] = '5-9';
$_SESSION['signup']['weight'] = 150;

In short, you manipulate it just like any other array.