multidimensional array remove item from child array - php

Question

i have a problem with my multidimensional array. I want to remove some items from child array by $id value.
here is my multidimensional example array and selectedIds:
$myArray = [
['id' => '2',
'name' => 'Punk'
],[
'id' => '5',
'name' => 'Rock',
'children' => [
'30' => ['id' => '30',
'name' => 'Hard Rock',
'parentId' => '5'
],
'40' => ['id' => '40',
'name' => 'Soft Rock',
'parentId' => '5'
],
'50' => ['id' => '50',
'name' => 'Glam Rock',
'parentId' => '5'
]
]
]
];
$selectedIds = [2,5,30];
and i want to remove from array those items which are not in selectedIds array.
so i want to have output:
$outputArray = [
[
'id' => '2',
'name' => 'Punk'
],[
'id' => '5',
'name' => 'Rock',
'children' => [
'30' => ['id' => '30',
'name' => 'Hard Rock',
'parentId' => '5']
]
]
];
i try to make it with foreach and array_key_exist but its not correct:
foreach ($myArray as $key=>$value) {
if (array_key_exists('children', $value)) {
foreach ($selectedIds as $id) {
if (isset($value['children'][$id])) {
$outputArray[] = $value['children'][$id];
}
}
}
}
print_r($outputArray);
this outpus is only item with id 30

Answer 1

write else part into your code if array has no children key
else{
foreach ($selectedIds as $id) {
if ($value['id'] == $id) {
$outputArray[$key] = $value;
}
}
}
Final code
<?PHP
$myArray = [
[
'id' => '2',
'name' => 'Punk'
],
[
'id' => '5',
'name' => 'Rock',
'children' => [
'30' => ['id' => '30',
'name' => 'Hard Rock',
'parentId' => '5'
],
'40' => ['id' => '40',
'name' => 'Soft Rock',
'parentId' => '5'
],
'50' => ['id' => '50',
'name' => 'Glam Rock',
'parentId' => '5'
]
]
]
];
$selectedIds = [2,5,30];
foreach ($myArray as $key=>$value) {
if (array_key_exists('children', $value)) {
foreach ($selectedIds as $id) {
if (isset($value['children'][$id])) {
$outputArray[$key]['id'] = $value['id'];
$outputArray[$key]['name'] = $value['name'];
$outputArray[$key]['children'][$id] = $value['children'][$id];
}
}
}else{
foreach ($selectedIds as $id) {
if ($value['id'] == $id) {
$outputArray[$key] = $value;
}
}
}
}
echo "<pre>";
print_r($outputArray);
?>
Output
Array
(
[0] => Array
(
[id] => 2
[name] => Punk
)
[1] => Array
(
[id] => 5
[name] => Rock
[children] => Array
(
[30] => Array
(
[id] => 30
[name] => Hard Rock
[parentId] => 5
)
)
)
)

Answer 2

Hey i make other code more simple. That´s here:
just change a bit the foreach content:
foreach ($myArray as $key=>&$value) {
if (array_key_exists('children', $value)) {
$value['children'] = array_intersect_key($value['children'], array_flip($selectedIds));
}
}
Use array_flipfor transform keys on values and array_intersect_keyfor get only they id´s that exist in 2 arrays.
here you can see a live demo
NOTE: take care that i´m passing the value by referer &$value in the foreach for modify the original array, if you dont want this just duplicate the original array and modify the second.