Array management in php - php

Question

Its generally related to a question in magento ..but i think using core php can also give me a wat i want
Im having a looping array issue here,My aray is like this
Array
(
[0] => Array
(
[category_id] => 2
[parent_id] => 1
[name] => Koffersenkisten
[is_active] => 0
[position] => 1
[level] => 1
[children] => Array
(
[0] => Array
(
[category_id] => 40
[parent_id] => 2
[name] => Muziek
[is_active] => 1
[position] => 1
[level] => 2
[children] => Array
(
[0] => Array
(
[category_id] => 46
[parent_id] => 40
[name] => Gitaar koffer
[is_active] => 1
[position] => 1
[level] => 3
[children] => Array
(
[0] => Array
(
[category_id] => 50
[parent_id] => 46
[name] => Bas gitaar koffer
[is_active] => 1
[position] => 1
[level] => 4
[children] => Array
(
)
)
[1] => Array
(
[category_id] => 51
[parent_id] => 46
[name] => Electrische gitaar koffer
[is_active] => 1
[position] => 2
[level] => 4
[children] => Array
(
)
)
[2] => Array
(
[category_id] => 47
[parent_id] => 46
[name] => Akoestische gitaar koffer
[is_active] => 1
[position] => 3
[level] => 4
[children] => Array
(
)
)
[3] => Array
(
[category_id] => 49
[parent_id] => 46
[name] => Gitaar soft cases
[is_active] => 1
[position] => 4
[level] => 4
[children] => Array
(
)
)
[4] => Array
(
[category_id] => 52
[parent_id] => 46
[name] => Gitaar gig bags
[is_active] => 1
[position] => 5
[level] => 4
[children] => Array
(
)
)
[5] => Array
(
[category_id] => 53
[parent_id] => 46
[name] => Pedalboards
[is_active] => 1
[position] => 6
[level] => 4
[children] => Array
(
)
)
[6] => Array
(
[category_id] => 48
[parent_id] => 46
[name] => Amp Utility Vehicles
[is_active] => 1
[position] => 7
[level] => 4
[children] => Array
(
)
)
)
)
[1] => Array
(
[category_id] => 67
[parent_id] => 40
[name] => Percussie koffer
[is_active] => 1
[position] => 2
[level] => 3
[children] => Array
(
[0] => Array
(
[category_id] => 73
[parent_id] => 67
[name] => Tom koffer
[is_active] => 1
[position] => 1
[level] => 4
[children] => Array
(
)
)
.......
......
>> it goes like this based on the number of categories
How do i get a simple array of the above like this
array('2' => 'Koffersenkisten','40'=> 'Muziek'...........etc); where 2 is the category_id and Koffersenkisten is the name

Answer 1

This function iterates over all items, and recurses when children are found. It passes the output array along at every invocation and appends to it:
function get_cats(array &$output, array $arr)
{
foreach ($arr as $item) {
$output[$item['category_id']] = $item['name'];
if (count($item['children'])) {
get_cats($output, $item['children']);
}
}
}
// start with empty result
$output = array();
get_cats($output, $a);
print_r($output);

Answer 2

This should work. Didn't test it.
$result = array();
function buildArray($array, $stack)
{
foreach($array as $item)
{
$stack[$item['category_id']] = $item['name'];
if(isset($item['children']) && count($item['children']) > 0)
foreach($item['children'] as $child)
buildArray($item['children'], &$stack);
}
}
buildArray($array, &$result);
print_r($result);

Answer 3

Here is a recursive solution (the array should be in $list before, the created array will be in $result after calling the create function):
function create($list, &$result) {
if (is_array($list) && !isset($list['category_id'])) {
foreach ($list as $element) {
create($element, $result);
}
} else {
$result[$list['category_id']] = $list['name'];
create($list['children'], $result);
}
}
create($list, $result);
Also see this example.