1

Say I have an array with keys representing id and values representing parent:

4  => 0
2  => 0
5  => 2
6  => 5
8  => 0
9  => 0
10 => 8
12 => 0
13 => 0
14 => 0
18 => 7
19 => 18
20 => 19
21 => 20
22 => 21
23 => 22
24 => 23
28 => 20
7  => 5

You could also read this as an object:

  { 
   id     : 4,
   parent : 0
  } // etc...

The multidimensional array I'd want to achieve from this would be:

4  => 0
2  => 5  
        => 6
        => 7
            => 18
                 => 19
                      => 20
                           => 21
                                 => 22
                                       => 23
                                             => 24
                           => 28
8  => 10
9  => 0
12 => 0
13 => 0
14 => 0

How would I go about doing this?

mickmackusa
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pat34515
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1 Answers1

3

If you write a little helper function to rework your data to a structure similar to:

$input = array(
  array('id' => '4', 'parent' => '0'),
  // ...
);

which could be achieved with something like:

$data = array_map(function ($entry) {
  list($id, $parent) = array_map('trim', explode('=>', $entry));
  return array(
    'id' => $id,
    'parent' => $parent
  );
}, explode("\n", $data));

you could then use a function I used in a similar question: 

function flatToNested($d, $r = 0, $p = 'parent', $k = 'id', $c = 'children') {
  $m = array();
  foreach ($d as $e) {
    isset($m[$e[$p]]) ?: $m[$e[$p]] = array();
    isset($m[$e[$k]]) ?: $m[$e[$k]] = array();
    $m[$e[$p]][] = array_merge($e, array($c => &$m[$e[$k]]));
  }
  return $m[$r];
}

to produce a nested array with:

$nested = flatToNested($data);

demo: http://codepad.viper-7.com/HAZxaA

Community
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Yoshi
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    What if the values are strings, i.e. `id=>'node-4',parent='node-0'`, instead of id=4 etc..? How could I modify this function? – pat34515 Jul 20 '12 at 10:39
  • @Patrick I don't think that this should be a problem, as long as they are unique `flatToNested` would handle it correctly. – Yoshi Jul 20 '12 at 10:44
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    @Patrick try: `$nested = flatToNested($doesntwork, 'node0');` The `$r` paramater to `flatToNested` selects the root node to return. – Yoshi Jul 20 '12 at 10:59