Remove elements from multidimensional array conditionally

Question

I have this array:

["balance"]=>
 array(5) {
 [0]=>
 array(3) {
 ["balance"]=>
 string(4) "0.00"
 ["id_item"]=>
 string(3) "540"
 ["item"]=>
 string(7) "Lampada"
 }
 [1]=>
 array(3) {
 ["balance"]=>
 string(4) "0.00"
 ["item"]=>
 string(6) "Taglio"
 ["id_item"]=>
 string(3) "541"
 }
 [2]=>
 array(3) {
 ["balance"]=>
 string(4) "0.00"
 ["item"]=>
 string(5) "Piega"
 ["id_item"]=>
 string(3) "542"
 }
 [3]=>
 array(3) {
 ["balance"]=>
 string(4) "2.00"
 ["item"]=>
 string(5) "Piega"
 ["id_item"]=>
 string(3) "542"
 }
 [4]=>
 array(3) {
 ["balance"]=>
 string(4) "7.00"
 ["item"]=>
 string(6) "Gelati"
 ["id_item"]=>
 string(3) "543"
 }

As you note, there are 2 arrays with a subkey "id_item" == 542. I need remove only the duplicate with a balance == 0. In detail I need remove the key == 2 (because the balance is 0 and there is another item with same ID with balance> 0)

This is my try but I cannot go further:

if ( is_array ( $array['balance'] ) && count ( $array['balance'] ) > 0 ) {
 foreach ( $array['balance'] as $key => $value ) {
 if ( isset ( $value['id_item'] ) ) {
 $id_item = $value['id_item'];
 // re-cycle on the array?
 // if next id_item == $id_item && value['balance'] == 0.00 remove
 }
 }
 }

• Sohel0415: what happens if you have duplicates and both have values for balance>0??
• sineverba: @Sohel0415 probably not possible. It is a patch for an old software. Thank you for interesting in this.!
• simon: Is the array sorted by id_item? So that all duplicates are next to each other?

Answer 1

I've tried to make it in few lines, check this out:

$array = [
 "balance" => [
 [
 "balance" => "0.00",
 "id_item" => "540",
 "item" => "Lampada",
 ],
 [
 "balance" => "0.00",
 "item" => "Taglio",
 "id_item" => "541",
 ],
 [
 "balance" => "0.00",
 "item" => "Piega",
 "id_item" => "542",
 ],
 [
 "balance" => "2.00",
 "item" => "Piega",
 "id_item" => "542",
 ],
 [
 "balance" => "7.00",
 "item" => "Gelati",
 "id_item" => "543",
 ]
 ]
];
//get array of id_items
$id_items = array_map(function($e) {
 return $e['id_item'];
}, $array['balance']);
//get duplicated keys
$duplicated_keys = array_keys(array_filter(array_count_values($id_items), function($v) {
 return $v > 1;
}));
//remove duplicated keys where balance is zero
foreach ($array['balance'] as $k => $balance) {
 if(in_array($balance['id_item'], $duplicated_keys) && $balance['balance'] == 0) {
 unset($array['balance'][$k]);
 }
}

• sineverba: Seems perfect. Thank you!