Variable variables

Shawazi

My server just got upgraded to version 5.0.2 for PHP. Variable variables are no longer working. Is there a new way to use them?

For instance,

$var = 512;
$512 = "Mark";

$$var should equal Mark but its not equal to anything now.

Installer

How sure are you that the code you posted will work on any version of PHP?

Shawazi

I'm not sure at all anymore. It worked through the previous upgrades I mean variable variables are in the handbook.

Shawazi

It turns out the new build is not liking variables named as numbers. Is there any way to change that?

The line
$512 = "Mark";

would not work. I think that is why it won't pass correctly. THe variables I used were coming through a form so i did not realize that until I tried it directly. if I do $a215 = "Mark" and $a = "a512", ${$a} works. It wont let $$a work though as it previously did.

rehfeld

it still comes down to that a variable name cannot begin w/ a number. theres nothing that can be done about it.

there is extract() though, and it can prefix variable names that begin w/ a number so that they are valid

Shawazi

Before 5.0.2, variables as numbers seemed to work.

The exact code was:

if ($delck)
{
	if ($$delck == "Delete")
	{
		mysql_query("delete from subcategories where id='$delck'");
		header("Location: $PHP_SELF");
	}
}

where the form went through a loop so each checkbox would be it's ID number

<input type='checkbox' value='$srow[id]' name='delck'> <input type='submit' name='$srow[id]' value='Delete'>

User would hit checkbox and then delete to ensure they deleted the correct category/product whatever.

So essentially if you checked the first thing and hit delete, the variables would equal the following and my PHP code would work.

$delck = 1;
$1 = "Delete";
$$delck = "Delete";

Are you sure there's no setting to allow numbers as variables again? Otherwise I need to go back and recode a lot of pages.

Installer

PHP has never allowed anything other than letters or the underline character as the first character in a variable name.

Shawazi

It never let it when it was flat out declared. But it would work when passed through a form with that trick. Guess I need to recode

Shrike

Variable variable names can start with numbers, I think PHP performs some trickery to do it:

function testing()
{
	$var = 1;
	$$var = "foobar"; // $$var is effectively named $1;
	print_r(get_defined_vars()); // look at the function vars to prove it : )
}
testing();

However a variable literally named $1 (or $512) won't work in any PHP version .