public class BankAccount {

    private double balance;
    private int accountNumber;
    private static int lastAssignedNumber = 1000;

    public BankAccount(double initBalance) {
        balance = initBalance;
        lastAssignedNumber++;
        accountNumber = lastAssignedNumber;
    }

    public String toString() { 
        return ("Account: " + accountNumber + " balance: " + balance);
    }

    public void setAccountNumber(int number) {
        accountNumber = number;
    }

}