BankAccount.php

<?php

final class BankAccount {
  private float $balance = 0;
  private readonly string $accountNumber;

  private function __construct(string $accountNumber) {
    $this->accountNumber = $accountNumber;
  }

  public static function create(string $accountNumber): self {
    if (empty($accountNumber)) {
      throw new \Exception("le numéro du compte ne doit pas être vide");
    }

    return new self($accountNumber);
  }

  public function deposite(float $amount): void {
    if ($amount <= 0) {
      throw new \Exception("Votre depot doit être >= 0");
    }

    $this->balance = $amount;
  }

  public function withdraw(float $amount): void {
    if ($amount > $this->balance) {
      throw new \Exception("vous ne pouvez retire plus que votre balance");
    }

    $this->balance -= $amount;
  }

  public function getAccountNumber(): string {
    return $this->accountNumber;
  }

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

$account = BankAccount::create("BA0993");
$account->deposite(100);
$account->withdraw(90);