object

<?php
include 'classes/Account.php';
include 'classes/Customer.php';

$accounts = [new Account(20489446, 'Checking', -20),
             new Account(20148896, 'Savings', 380),];
$customer = new Customer('홍길동', 'ivy@eg.link', 'Jup!t3r2684', $accounts);
?>

<h2>이름: <?= $customer->name ?></h2>
<table>
  <tr>
    <th>계좌번호</th>
    <th>계좌종류</th>
    <th>잔고</th>
  </tr>
  <?php foreach ($customer->accounts as $account) { ?>
  <tr>
        <td><?= $account->number ?></td>
        <td><?= $account->type ?></td>
          <?php if ($account->getBalance() >= 0) { ?>
        <td class="credit">
            <?php } else { ?>
        <td class="overdrawn">
            <?php } ?>
        <?= $account->getBalance() ?></td>
  </tr>
  <?php } ?>
</table>

customer

<?php
class Customer
{
    public  string $name;
    public  string $email;
    private string $password;
    public  array  $accounts;

    function __construct(string $name, string $email,string $password, array $accounts)
    {
        $this->name = $name;
        $this->email    = $email;
        $this->password = $password;
        $this->accounts = $accounts;
    }
}

account

<?php
class Account {
    public    int    $number;
    public    string $type;
    protected float  $balance;

    public function __construct(int $number, string $type, float $balance = 0.00)
    {
        $this->number  = $number;
        $this->type    = $type;
        $this->balance = $balance;
    }

    public function deposit(float $amount): float
    {
        $this->balance += $amount;
        return $this->balance;
    }

    public function withdraw(float $amount): float
    {
        $this->balance -= $amount;
        return $this->balance;
    }

    public function getBalance(): float
    {
        return $this->balance;
    }
}