PHP array as variable name

Question

How to send an indexes name for php array vairable.

the array is

$array = array('Somthing'=>array('More'=>array('id'=> 34)));

and now I want to display this thing but with a variable name I don't know how to explain so I write what I want to have.

$index_name = '[Something][More][id]';

$array{$index_name};

Is it possible in any way ?

Answer 1

Not in one go like that. Here's how you'd do it:

$array['Something']['More']['id']

If you particularly wanted access multidimensional arrays with a single string, then you could build a function to do that:

function array_multi(Array $arr, $path) {
    $parts = explode(".", $path);

    $curr =& $arr;
    for ($i = 0, $l = count($parts); $i < $l; ++$i) {
        if (!isset($curr[$parts[$i]])) {
            // path doesn't exist
            return null;
        } else if (($i < $l - 1) && !is_array($curr[$parts[$i]]) {
            // path doesn't exist
            return null;
        }
        $curr =& $curr[$parts[$i]];
    }
    return $curr;
}

// usage:
echo array_multi($array, "Something.More.id");    // 34
echo array_multi($array, "Something.More");       // array("id" => 34)

Answer 2

You could do this with eval():

<?php

$array = array('Somthing'=>array('More'=>array('id'=> 34)));
$index_name = "['Somthing']['More']['id']";

$stmt='echo $array'.$index_name.';';
eval($stmt);

?>

---

UPDATE:

It seems some SO users are uncomfortable with the idea of using eval(). I think it makes sense to read this thread which discusses the pros and cons before deciding whether to use this in your own code.

Answer 3

Ok, I know this is how people get shot. But c'mon, eval() is not always the wrong answer.

$array = array('Something'=>array('More'=>array('id'=> 34)));
$index_name = '[Something][More][id]';
eval('$val = $array'.$index_name.';'); // Wrap in a function or something

Answer 4

Recursive version supporting your syntax with square brackets:

$array = array('Something'=>array('More'=>array('id'=> 34)));

$string = '[Something][More][id]';

echo scan_array($string, $array);

function scan_array($string, $array) {
    list($key, $rest) = preg_split('/[[\]]/', $string, 2, PREG_SPLIT_NO_EMPTY);
    if ( $key && $rest ) {
        return scan_array($rest, $array[$key]);
    } elseif ( $key ) {
        return $array[$key];
    } else {
        return FALSE;
    }
}

Answer 5

If you've cornered yourself into needing to do something like this, there's a pretty good chance you've done something else in a poor way. There's valid reasons to do this, but not very often.

function key_path($arr, $keys) {
    return $keys ? key_path($arr[array_shift($keys)], $keys) : $arr;
}

$arr['Something']['More']['id'] = 34;
$keys = array('Something', 'More', 'id');

var_dump( key_path($arr, $keys));