Static Builder and Create Methods for simple class

[Pilot Ace]

I was told by my instructor to include a static builder method and static create method as part of good class design in all my programs, the problem is, I don't understand how I would use other non-static methods associated with the class. Here are the two methods:

public static BankAccount Create(String name, int accountNumber, double balance)           
    {
        BankAccount anAccount = null;
        anAccount = new BankAccount(name, accountNumber, balance);
        return anAccount;
    }

public static BankAccount Builder()    
    {
        BankAccount anAccount = new BankAccount();
        return anAccount;
    }

If I use these methods with a class named BankAccount, like

BankAccount.Create(Johnson, 3233, 100)

how (if it is even possible) can I use non-static methods like 'withdraw' or 'deposit' to modify the balance or other instance variables? The static methods create a new account, 'anAccount', but I cannot use non-static methods with anAccount.withdraw. I simply just don't understand what the purpose of these static methods in a class are if non-static methods cannot be used. Please help!

[pbrockway2]

In some other class you can say:

BankAccount ac = BankAccount.create(Johnson, 3233, 100);
ac.deposit(100.00);

Of course the reference ac has to be stored somewhere - like a list of bank accounts - otherwise it will no longer be accessible when the method that called create() has ended.

[Pilot Ace]

Thanks for the help.

[pbrockway2]

You're welcome.