variable inside a variable

russthebarber

yes its that old one again!

but this time i am having real problems.

i am doing a tracklisting for a radio station, where they fill out a form with track 01, 02, 03 etc details and each of these is saved with variables i.e. $track01_artist, track_01title, $track01_label etc.

i have a table (html) where the tracks are listed. to save space i need the table to only have 6 rows if there are only 6 tracks in the list and only 7 rows if there are only 7 tracks etc etc.

so i have a php variable $counter and i am using a standard loop where id the user has entered 6 as the number of tracks, the loop runs 6 times and my variable names use the $counter variable within them, except i cannot get the **** to work, because php won't understand my variable $counter inside the variable $track01_artist for example.

here's a section of what i have with some notes:

<? $counter=1;

while ($counter<=$tracks_number)
{
?>

<tr>
<td>Track <? print("0$counter"); ?>: </td>//this works fine!
<td><? print("$track_0{$counter}artist"); ?>//this doesn't work????
//it actually returns "1artist", "2artist" etc. etc.
//the following ones have the same problem

, <? print("$track_0{$counter}title"); ?>, <? print("$track_0{$counter}label"); ?></td>
</tr>
<? $counter++;
}
?>

OK, any help greatly appreciated.

virtualdevl

<td><? "$track_0" . $counter . "artist"; ?></td>

laserlight

It looks like you are trying to use variable variables. However, it may be better to use arrays instead.

russthebarber

many thanks for trying to help guys, but i still have the same problem.
i tried this:
<td><? "$track_0" . $counter . "artist"; ?>

and it didnt work. it actually prints this:
1artist, 1title, 1label

i also tried this:
<td><? echo ("$track_0" . $counter . "artist"); ?>

didnt work either.

the variable variables is not really what i am looking for.......i don't think. i can't find a way to get that system to help me.

i am truely stuffed. unless anyone has any ideas.

virtualdevl

What is it that you want it to print? Some thing like this?

<td>track00_artist_name</td>
<td>track01_artist_name</td>
<td>track02_artist_name</td>

What is $tracks_number? Where is the value? Is $track_0 an array?

Maybe?? I would really need to seee the track stuff

<td><?php echo $track[0][$counter]['artist']; ?></td>

russthebarber

here's what i am trying to achieve:

i want the name of my variable in the loop to change with the $counter. so if i have the following variables already set from the user's form data for example:

$tracks_number="4"; //number of tracks in the list

$track_01artist="michael jackson";
$track_01title="billy jean";
$track_01label="sony music";

$track_02artist="frank sinatra";
$track_02title="my way";
$track_02label="bla bla label";

$track_03artist="acdc";
$track_03title="hells bells";
$track_03label="atlantic";

$track_04artist="dj bozo";
$track_04title="bla bla";
$track_04label="some label";

i want to see the track list as follows:

michael jackson, billy jean, sony music
frank sinatra, my way, bla bla label
acdc, hells bells, atlantic
dj bozo, bla bla, some label

so by using the $counter i want to effectively change the name of the $track_01artist variable to $track_02artist and so on until the

$tracks_number="4"; //number of tracks in the list

reaches 4. i am rewriting the name of the variable each time. at least that is what i am trying to do.

virtualdevl

Hey, I'm heading out for the day, I'll take a look at this later tonight if you have not resolved. I would really suggest you use arrays for this.

russthebarber

ok, i have solved this with arrays which is good. but i still would love to know how to do this for the future without arrays. sometimes arrays are an incredibly long way round, although they often work. there must be a better way.

thanks very much for your time and effort, anyway. 😉

Neumy

Hey russthebarber,

I'm not sure this is the best way to solve your problem, but I took your two examples and tried to create code to fit with the solution you were aiming for.

-) I didn't like the 01, 02, 03 ... you had in your variables. I know you can come up with some solution, but it was easier to just remove the zero.
-) I stayed away from the while loop and went with a for loop. At least to me, your request screamed for a for loop 😉

$tracks_number="4"; //number of tracks in the list

$track_1artist="michael jackson";
$track_1title="billy jean";
$track_1label="sony music";

$track_2artist="frank sinatra";
$track_2title="my way";
$track_2label="bla bla label";

$track_3artist="acdc";
$track_3title="hells bells";
$track_3label="atlantic";

$track_4artist="dj bozo";
$track_4title="bla bla";
$track_4label="some label";

for($i=1;$i<=$tracks_number;$i++)
{
	$varArtist = 'track_'.$i.'artist';
	$varTitle = 'track_'.$i.'title';
	$varLabel = 'track_'.$i.'label';
	echo "{$i}. {$$varArtist}, {$$varTitle}, {$$varLabel}<br>";
}

Installer

echo ${'track_0' . $counter . 'artist'};

sometimes arrays are an incredibly long way round, although they often work. there must be a better way.

:rolleyes: