Help Transfering Money in Account Class

Question

Hi, i had a task where i have to add some feature to a account class. I have done the first two (checking if in credit, and applying a credit charge) but i am having trouble with the transfer one. Money has to be transfered from "from" to the account. The tip says the following.
"Send the message to withdraw to the object passed as a parameter. Then you will need to add the withdrawn amount to the balance in the current account. Remember the object from is a seperate account and is passed by reference. Consequence of passing the handle to the object by value. So that all changes made to the formal parameter from are made to the actual object that is passed."
My question is that how do i set up the reference to the account from, as i am unsure how to, as how i have it at the moment is just withdrawing from the current account? Also at the moment i have
"getBalance()=getBalance()+amount;" why will it not allow this as they are all double?
Super class
class Account
  private double theBalance    = 0.00;   // Balance of account
  private double theMinBalance = 0.00;   // Minimum bal (Overdraft)
  public double getBalance()
    return theBalance;
  public double withdraw( final double money )
    assert money >= 0.00;
    if ( theBalance - money >= theMinBalance )
      theBalance = theBalance - money;
      return money;
    } else {
      return 0.00;
  public void deposit( final double money )
    assert money >= 0.00;
    theBalance = theBalance + money;
  public void setMinBalance( final double money )
    theMinBalance = money;
  public double getMinBalance()
    return theMinBalance;
}And my subclass
public class AccountBetter extends Account
boolean a;
double charge;
double newbal;
double awooga;
public boolean in_credit(){
if (getBalance()>0.00)
a = true;
else
{a = false;
return a; }
public void credit_charge()
{if (getBalance()<0.00)
{charge = getBalance() * -0.00026116;
if (withdraw(charge)>getMinBalance()){
setMinBalance(getMinBalance()-charge);
withdraw(charge);
public void transfer (AccountBetter from, double amount)
withdraw(amount);
getBalance()=getBalance()+amount;
}

Answer 1

Hi, i had a task where i have to add some feature to a
account class. I have done the first two (checking if
in credit, and applying a credit charge) but i am
having trouble with the transfer one. Money has to be
transfered from "from" to the account. The tip says
the following.Finally somebody who's posting code, asking precise questions and makes sense :-)
"Send the message to withdraw to the object passed as
a parameter. Then you will need to add the withdrawn
amount to the balance in the current account. Remember
the object from is a seperate account and is passed by
reference. Consequence of passing the handle to the
object by value. So that all changes made to the
formal parameter from are made to the actual object
that is passed."Pass-by-reference v.s. pass-by-value
Search on that in this forum, you'll find about everything you ever want to know (and don't want to know) about it.
My question is that how do i set up the reference to
the account from, as i am unsure how to, as how i have
it at the moment is just withdrawing from the current
account?Imagine 2 account objects, method calls with parameters and calling methodson both objects.
(Also remember the pass-by-reference thingies you spent time on reading here in the forum :-P )
Also at the moment i have
"getBalance()=getBalance()+amount;" why will it not
allow this as they are all double?This won't ever work, sorry about that, but no luck there.
You cannot assign a value to a method call.
<snip-code />
I would take a look at the coding standards while you were at it,
for example: the method credit_change is not according to the, general accepted, coding standards ;-)
About your problem,
the signature of the transfer money is sufficient but think about the following:
- Where do i want to transfer from?
- Where do i want to transfer to?
- Can i assign values to a method or can i only do that to variables that are visible in the scope i'm working in?
- Are there any other methods I could use, for example inherited ones?