[RESOLVED] evaluate string as variable name

[cretaceous]

I'm building an xml excel spreadsheet on the fly (using the Pear class) and I want to be able to change the number of the last variable ($format_3) dynamically:

$sheet->write($xlsrow,$i,$thistrade,$format_3);

so I want to code automatically for $format_1, $format_2 etc

a simple concat $format_.$myvar doesnt work

and a variable variable :

$foo = 'format_'.$myvar;
$ref = "foo";
echo $$ref;

does not work when used in the xml function though the simple echo appears correct

I could do it with a clunky switch statement but there must be a better way -
any ideas?

[Installer]

$sheet->write($xlsrow,$i, $thistrade, ${'format_' . $i});

But for even less clunkiness, use arrays rather than numbered variables.

[zany_cynic]

Hi. I'm having this problem on converting a String value into a variable.

I have this function that accepts 2 paramters an associative array and an array that contains the keys.

$array_keys = array('key1', 'key2', 'key3');
$array_data = array('key1' => array('key2' => array('key3' => 'value1')));
function get_arr_data($array_data, $array_keys){
  foreach ($array_keys as $key){
    $keys .= "['$key']";
  }

  $data = "\$array_data".${$keys};
  //expected data of $array_data['key1']['key2']['key3']
  return ${$data};
}

This function must return the data of the associative array but I'm always getting NULL even if there is data on it. When I tried to return only $data (without${}) I'm getting the string value of $data.
Any help? thanks

[Weedpacket]

Wouldn't

function get_arr_data($array_data, $array_keys){
$data = $array_data;
foreach($array_keys as $key)
    $data = $data[$key];
return $data;
}

be simpler? Certainly less confusing (I doubt variable names can contain [ ] characters, so having those in a string $data would make ${$data} invalid.)

[zany_cynic]

Thanks Weedpacket, but the $array_data I'm dealing with is dynamic.. which means that it may be a nested associative arrays. That is why I am passing in an array of $array_keys which consist of the hierarchical keys of the array that I would like to retrieve. That is why I'm putting the keys in a String

foreach ($array_keys as $key){
    $keys .= "['$key']";
}

and appending it to the $array_data

Hence $array_data['key1']['key2']['key3']

any other ideas?