Dynamic Named Vars

frigidman

I'm trying to figure out how one goes about doing something like the below:
(please note this is of the most basic example...)

$this1 = "Somevalue";
$this2 = "AnotherValue";
$n = rand(1,2);
echo $this$n;

Apparently it gives parse errors. I've tried to use the curly bracks like:

echo {$this$n};
or
echo ${this$n};

But am not finding the right combination. Whats the proper syntax to retrieving a value by 'dynamically building' the varname to use? This is such common place in every other language, so it has GOT to be feasible in PHP...

amcgrath

Would putting them into an array work for you? Either way, this worked for me, though there's gotta be a cleaner way:
$this1 = "Somevalue";
$this2 = "AnotherValue";
$n = rand(1,2);
$dyn_value = "this" . $n;
echo $$dyn_value;

frigidman

Hmm. Yeah, that works. Odd... I can't imagine why it would create the name of the var on the fly like my example.

I guess for everytime I will need a dynamic name, I will have to "create the FULL name" right before I try to hit the var of that name by using the $$.

Eeek... talk about doubling your code for no good reason. Like original code of:

	$tid_q = addslashes($tid$n);
	$name_q = addslashes($name$n);
	$toollink_q = addslashes($toollink$n);
	$listorder_q = addslashes($listorder$n);

(the above gives parse errors)

ends up looking like:

	$DYN = "tid".$n;
	$tid_q = addslashes($$DYN);
	$DYN = "name".$n;
	$name_q = addslashes($$DYN);
	$DYN = "toollink".$n;
	$toollink_q = addslashes($$DYN);
	$DYN = "listorder".$n;
	$listorder_q = addslashes($$DYN);

(the above actually WORKS, buts its ugly)

Imagine that junk in a FOR loop setting up POST data to be inserted each into a database. Thats a mild example of where I use dynamic referenced vars.

Thanks for the tip though! At least I can get it working in limping fashion ;-)

SOME things I am able to convert to arrays (using the empty square bracks in FORM NAME settings)... however some are just 'too' dynamic to convert to arrays effectively without creating about 5 times the code for something so basic.

Anon

alternatively, you can use this notation:

$this1 = "Somevalue";
$this2 = "AnotherValue";
$n = rand(1,2);
echo ${'this'.$n}

this elimiates that extra line of code; you don't have to create a name for each variable.

frigidman

AH HA! Thats it... yeah, thanks!

I just didn't far enough with the curly bracks I guess. I'm wondering why I can't find any reference to this (either of these) solutions in any online manuals, or the two thick books I have... strange.

Anyhow, yes, this works great (both solutions), thanks!