CashDispenser.java

// CashDispenser.java
// Represents the cash dispenser of the ATM

public class CashDispenser {
    // the default initial number of bills in the cash dispenser
    private final static int INITIAL_COUNT = 500;
    private int count; // number of $20 bills remaining

    // no-argument CashDispenser constructor initializes count to default
    public CashDispenser() {
        count = INITIAL_COUNT; // set count attribute to default
    } // end CashDispenser constructor

    // simulates dispensing of specified amount of cash
    public void dispenseCash(int amount) {
        int billsRequired = amount / 20; // number of $20 bills required
        count -= billsRequired; // update the count of bills
    } // end method dispenseCash

    // indicates whether cash dispenser can dispense desired amount
    public boolean isSufficientCashAvailable(int amount) {
        int billsRequired = amount / 20; // number of $20 bills required

        if (count >= billsRequired)
            return true; // enough bills available
        else
            return false; // not enough bills available
    } // end method isSufficientCashAvailable
} // end class CashDispenser