<?php

class BankAccount
{
    private $number;
    private $balance;

    public function __construct($number)
    {
        $this->number = $number;
        $this->balance = 0;
    }

    public function getNumber()
    {
        return $this->number;
    }

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

    public function depositCash($amount)
    {
        if (is_numeric($amount) && $amount > 0) {
            $this->balance += $amount;
        } else {
            echo 'Złe dane!';
            return false;
        }
    }

    public function withdrawCash($amount)
    {
        if (is_numeric($amount) && $amount > 0) {
            if ($this->balance < $amount) {
                return $this->balance;
            }

            $this->balance -= $amount;
        } else {
            echo 'Złe dane!';
            return false;
        }

        return $this->balance;
    }

    public function printInfo()
    {
        return "ID konta: {$this->getNumber()}, Saldo: {$this->getBalance()}zł.<br><br>";
    }
}

$account1 = new BankAccount(1233654654);

echo $account1->printInfo();//Puste konto

$account1->depositCash(500); //Dodajemy 500 na konto
echo $account1->printInfo();//Jest 500 na koncie

$account1->withdrawCash(152); //Wyciągamy 152 na konto
echo $account1->printInfo();//Jest 348 na koncie


echo $account1->withdrawCash(500);//Ile nam pozostało