有条件地从多维数组中删除元素

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

                        }

                    }

                }

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]);
    }
}