Recursive array structured

Question

Possible Duplicate:
String with array structure to Array

I have an array as such

$foo = array();
$foo['/'] = 'value';
$foo['/foo'] = 'value';
$foo['/foo/bar'] = 'value';
$foo['/test'] = 'value';
$foo['/test/tester'] = 'value';
$foo['/hello'] = 'value';
$foo['/hello/world'] = 'value';
$foo['/hello/world/blah'] = 'value';

What I need to do is store these sub-pages in a tree-like structure, so instead it needs to be automatically converted to:

   $foo = array(
    '/' => array(
        'value' => 'value',
        'children' => array(
            '/foo' => array(
                'value' => 'value',
                'children' => array(
                    '/foo/bar' => array(
                        'value' => 'value',
                        'children' => array()
    );

What I figured I would be doing, is something like:

$newArray = array();
foreach( $foo as $key => $val )
{
    $bits = explode('/', $key);

    foreach( $bits as $bit )
    {
        $newArray[$bit] = array('val' => $val);
    }
}

print_r($newArray);

Except I somehow need to go into the newArray, and keep track of how deep I am into the array. Does anyone have an example script of how they have done so, or have any funky array walk tips to do so?

Please go and learn about recursion. – blockhead Jun 14 '12 at 16:49 — blockhead, Jun 14 '12 at 16:49
@blockhead: http://stackoverflow.com/a/23882 – Rocket Hazmat Jun 14 '12 at 16:52 — Rocket Hazmat, Jun 14 '12 at 16:52

score 3 · Accepted Answer · answered Jun 14 '12 at 17:38

The solution can be achieved with variable references (aka "pointers"), for more information see http://php.net/manual/en/language.references.php

<?php

$foo = array();
$foo['/'] = 'value';
$foo['/foo'] = 'value';
$foo['/foo/bar'] = 'value';
$foo['/test'] = 'value';
$foo['/test/tester'] = 'value';
$foo['/hello'] = 'value';
$foo['/hello/world'] = 'value';
$foo['/hello/world/blah'] = 'value';

function nest(&$foo)
{
    $new = array();
    foreach ($foo as $path => $value)
    {
        $pointer =& $new;
        $currentPath = '';
        if ($pathParts = explode('/', trim($path, '/'))) {
            while($nextKey = array_shift($pathParts)) {
                $currentPath .= '/' . $nextKey;
                if (!isset($pointer['children'][$currentPath])) {
                    $pointer['children'][$currentPath] = array();
                }
                $pointer =& $pointer['children'][$currentPath];
            }
        }
        $pointer['value'] = $value;
    }
    return $new ? array('/' => $new) : array();
}

print_r($foo);
print_r(nest($foo));

?>

Note that this example is called "iterative" because it does not use recursion. I'm not sure what a recursive version would look like but I invite @blockhead or someone else to try :-) — jchook, Jun 14 '12 at 19:30

Recursive array structured

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