如何分组数组元素？

Question

I've an array of folders/paths:

$arr = Array
(
    0 => Array
         (
              'name' => 'aaa'
         ),

    1 => Array
         (
              'name' => 'aaa\bbb'
        ),

    2 => Array
         (
              'name' => 'aaa\bbb\ccc'
         ),
    3 => Array
         (
              'name' => 'ddd'
         )
);

I'd like to transform it to multidimensional (tree-like) array (keeping the structure: index/key & value/name):

 aaa 
    bbb
       ccc
 ddd

Any suggests?

Answer 1

Try:

$arr = array(
   array('name' => 'aaa'),
   array('name' => 'aaa\bbb'),
   array('name' => 'aaa\bbb\ccc'),
   array('name' => 'ddd'),
   array('name' => 'ddd\zzz'),
   array('name' => 'zzz'),
   array('name' => 'ddd\zzz\fff'),
);

$new = array();
$helper = array();
foreach ($arr as $i => $entry) {
    $parent =& $new;
    /**
     * One could use:
     *   explode(DIRECTORY_SEPARATOR, $entry['name'])
     * 
     * instead of '\\' if you're dealing with file-structures
     */
    foreach ($path = explode('\\', $entry['name']) as $ii => $element) {
        $subPath = implode('.', array_slice($path, 0, $ii + 1));

        if (isset($helper[$subPath])) {
            $parent =& $helper[$subPath];
            continue;
        }

        $parent[$i] = array('name' => $element);
        $helper[$subPath] =& $parent[$i];
    }
}

print_r($new);

Output :

Array
(
    [0] => Array
        (
            [name] => aaa
            [1] => Array
                (
                    [name] => bbb
                    [2] => Array
                        (
                            [name] => ccc
                        )

                )

        )

    [3] => Array
        (
            [name] => ddd
            [4] => Array
                (
                    [name] => zzz
                    [6] => Array
                        (
                            [name] => fff
                        )

                )

        )

    [5] => Array
        (
            [name] => zzz
        )

)

Answer 2

$newarr=array();

foreach ($arr as $element) {
    $currentroot=$newarr;
    $pieces=explode('\\', $element);
    for ($x=0; $x<=count($pieces); x++) {
        $currentroot[$pieces[$x]]=array();
        $currentroot=$currentroot[$pieces[$x]];
    }
}

Untested but should get you started. You need to add a condition to check if it is the last piece, and make it a string value instead of an array.

Answer 3

For the new requirements:

$arr = array(
   array('name' => 'aaa'),
   array('name' => 'aaa\bbb'),
   array('name' => 'aaa\bbb\ccc'),
   array('name' => 'ddd'),
);

function traverse(array $array) {
    $mark=array_shift($array);
    return array($mark => $array ? traverse($array) : array() );
}

$out = array();
foreach($arr as $path)
{
    ($add=traverse(explode('\\',$path['name'])))
        && $out[key($add)]=current($add)
        ;
}

Output:

array(2) {
  ["aaa"]=>
  array(1) {
    ["bbb"]=>
    array(1) {
      ["ccc"]=>
      array(0) {
      }
    }
  }
  ["ddd"]=>
  array(0) {
  }
}

Old Question:

The old question had these reqs:

$arr = array(
   0 => 'aaa',
   1 => 'aaa\bbb',
   2 => 'aaa\bbb\ccc',
);

function traverse(array $array) {
    $mark=array_shift($array);
    return $array ? array($mark => traverse($array)) : $mark;
}

$out = array();
foreach($arr as $path)
{
    is_array($add=traverse(explode('\\',$path)))
        && $out[key($add)]=current($add)
        ;
}

Tested, giving this output:

array(1) {
  ["aaa"]=>
  array(1) {
    ["bbb"]=>
    string(3) "ccc"
  }
}

Answer 4

Well, had to do it in two functions, but here goes:

// Directory Array to Hierarchy
function _DAtoH($path, $result = null)
{    
  if (empty($path))      return array();
  if (is_null($result))  $result = array();

  $path = explode(DIRECTORY_SEPARATOR, $path);
  $curr = array_shift($path);
  if (!isset($result[$curr]))
    $result[$curr] = array();
  $result[$curr] = _DAtoH(implode(DIRECTORY_SEPARATOR, $path), $result[$curr]);
  return $result;
}
function DAtoH($arr)
{
  $result = array();
  foreach ($arr as $a)
    $result = _DAtoH($a,$result);
  return $result;
}

Passing the bottom function (the _DAtoH is just a recursive helper) the array you specified in your original question ( var_dump(DAtoH($arr)); ), you should receive:

array(2) {
  ["aaa"]=>
  array(2) {
    ["bbb"]=>
    array(1) {
      ["ccc"]=>
      array(0) {
      }
    }
    ["fff"]=>
    array(0) {
    }
  }
  ["ddd"]=>
  array(1) {
    ["eee"]=>
    array(0) {
    }
  }

}

(Note: I added some folder paths just to test it out, thus the fff, eee, etc.)