php multidimensional array from known key values

Question

Hi all,

I have a collection of keys in this massive flat single array I would like to basically expand that array into a multidimensional one organized by keys - here is an example:

'invoice/products/data/item1'
'invoice/products/data/item2'
'invoice/products/data/item2'

=>

'invoice'=>'products'=>array('item1','item2','item3')

how can I do this - the length of the above strings are variable...

Thanks!

Answer 1

Something along these lines: (Didn't test it though!) Works now ;)

$data = array();
$current = &$data;
foreach($keys as $value) {
  $parts = explode("/", $value);
  $parts_count = count($parts);
  foreach($parts as $i => $part) {
    if(!array_key_exists($part, $current)) {
      if($i == $parts_count - 1) {
        $current[] = $part;
      }
      else {
        $current[$part] = array();
        $current = &$current[$part];
      }
    }
    else {
      $current = &$current[$part];
    }
  }
  $current = &$data;
}

$keys beeing the flat array.

Answer 2

Although it's not clear from your question how the "/" separated strings will map to an array, the basic approach will probably be something like this:

$result = array();
$k1 = $k2 = '';
ksort($yourData); // This is the key (!)
foreach ($yourData as $k => $v) {
  // Use if / else if / else if to watch for new sub arrays and change
  // $k1, $k2 accordingly
  $result[$k1][$k2] = $v;
}

This approach uses the ksort to ensure that keys at the same "level" appear together, like this:

'invoice/products/data1/item1'
'invoice/products/data1/item2'
'invoice/products/data2/item3'
'invoice/products2/data3/item4'
'invoice/products2/data3/item5'

Notice how the ksort corresponds to the key grouping you're aiming for.

Answer 3

$src = array(
'invoice/products/data/item1',
'invoice/products/data/item2',
'invoice/products/data/item2',
'foo/bar/baz',
'aaa/bbb'
);

function rsplit(&$v, $w)
{
    list($first, $tail) = explode('/', $w, 2);
    if(empty($tail)) 
    {
        $v[] = $first;
        return $v;
    }
    $v[$first] =  rsplit($v[$first], $tail);
    return $v;

}

$result = array_reduce($src, "rsplit");
print_r($result);

Output is:

Array (
    [invoice] => Array
        (
            [products] => Array
                (
                    [data] => Array
                        (
                            [0] => item1
                            [1] => item2
                            [2] => item2
                        )

                )

        )

    [foo] => Array
        (
            [bar] => Array
                (
                    [0] => baz
                )

        )

    [aaa] => Array
        (
            [0] => bbb
        )

)