Empty cells get skipped (would like to replace it with 0)

[ignaaaam]

Hello, at the moment, cells that contains 0 works well, but when the cell is empty it gets skipped and I would like to fill those empty cells with 0.

What I'm doing is import the excel, take every billing per month and adding at the end of the year on 31st of december the total amount of billing during that year. But the problem is empty cells (if there's 0 it gets it as 0) get skipped. So if from 2022-05-01 to 2022-08-01 it's empty will get those months skipped.

What I have at the moment is:

public function model(array $row)
    {
        $date = Carbon::now();
        $date->year = $this->year;
        $date->day = 1;

        $clientCode = $row['id_client'];
        $totalAmount = $row['total'];
        $client = Client::where('code', $clientCode)->first();


        foreach ($row as $key => $dirtyAmount) {
            if (!$client) {
                continue;
            }
            if (is_null($dirtyAmount)) {
                continue;
            }

            $excludeColumn = false;

            switch ($key) {
                case 'january':
                    $date->month = 1;
                    break;
                case 'february':
                    $date->month = 2;
                    break;
                case 'march':
                    $date->month = 3;
                    break;
                case 'april':
                    $date->month = 4;
                    break;
                case 'may':
                    $date->month = 5;
                    break;
                case 'june':
                    $date->month = 6;
                    break;
                case 'july':
                    $date->month = 7;
                    break;
                case 'august':
                    $date->month = 8;
                    break;
                case 'september':
                    $date->month = 9;
                    break;
                case 'october':
                    $date->month = 10;
                    break;
                case 'november':
                    $date->month = 11;
                    break;
                case 'december':
                    $date->month = 12;
                    break;
                default:
                    $excludeColumn = true;
                    break;
            }

            if ($excludeColumn) {
                continue;
            }

            $billing = new Billing([
                'amount' => Money::parse($dirtyAmount),
                'billing_date' => $date,
            ]);

            $client->billings()->save($billing);

            if ($date->month == 12) {

                $billing = new Billing([
                    'amount' => Money::parse($dirtyAmount),
                    'billing_date' => $date,
                ]);

                if (isset($dirtyAmount)) {
                    $billingTotal = new Billing([
                        'amount' => Money::parse($totalAmount),
                        'billing_date' => $date->year . '-12-31 23:59:59',
                    ]);
                    $client->billings()->save($billingTotal);
                } else {
                    $billingTotal = new Billing([
                        'amount' => 0,
                        'billing_date' => $date->year . '-12-31 23:59:59',
                    ]);
                    $client->billings()->save($billingTotal);
                }
            } else {
                continue;
            }
        }
        return;
    }

[ignaaaam]

Okay my mistake, got already solved.