How to pass a variable between methods without parameters and arguments

Question

I'm having a bit of an issue with a school project of mine. We're supposed to write a Loan class that will do things associated with, well, loans, such as return the monthly payment and the total payment on the loan. My problem is that I have specific instructions for this code that I absolutely cannot go outside of. Here's the code:

    import java.util.Scanner;
    import java.text.DecimalFormat;
    import java.lang.Math;

    public class Loan
    {
        public double annualInterestRate = 0;
        public int numberOfYears = 0;
        public double loanAmount = 0;

        public Loan()
        {
            annualInterestRate = 0.025;
            numberOfYears = 1;
            loanAmount = 1000;
        }

        public Loan(double interestRate, int numYears, double amount)
        {
            setRate(interestRate);
            setYears(numYears);
            setLoanAmount(amount);
        }

        public void setRate(double interest)
        {
        DecimalFormat percent = new DecimalFormat( "0.0%" );
            if(interest > 25 || interest < 0)
            {
                System.out.println("WARNING: Invalid annual interest rate: " + percent.format(interest) + ".");
                System.out.println("Current value not changed: " + percent.format(annualInterestRate * 100) + ".");
            }
            else
            {
                annualInterestRate = interest;
            }
        }

        public void setYears(int years)
        {
            if(years > 30 || years <= 0)
            {
                System.out.println("WARNING: Invalid number of years: " + years + ".");
                System.out.println("Current value not changed: " + numberOfYears + ".");
            }
            else
            {
                numberOfYears = years;
            }
        }

        public void setLoanAmount(double amnt)
        {
            DecimalFormat loan = new DecimalFormat( "$#,##0.00" );
            if(amnt <= 0)
            {
                System.out.println("WARNING: Invalid loan amount: " + loan.format(amnt) + ".");
                System.out.println("Current value not changed: " + loan.format(amnt) + ".");
            }
            else
            {
                loanAmount = amnt;
            }
        }

        public double getAnnualInterestRate()
        {
            return annualInterestRate;
        }

        public int getNumberOfYears()
        {
            return numberOfYears;
        }

        public double getLoanAmount()
        {
            return loanAmount;
        }

        public double getMonthlyPayment()
        {
            double monthly = annualInterestRate/12;
            double monthlyPayment = (loanAmount * monthly)/1 - (1/(1 + monthly));
            monthlyPayment = Math.pow(monthlyPayment, 12);
            return monthlyPayment;
        }

        public double getTotalPayment()
        {
            double totalPayment = getmonthlyPayment() * 12;
            return totalPayment;
        }

        public String toString()
        {
            DecimalFormat percent = new DecimalFormat( "0.0%" );
            DecimalFormat loan = new DecimalFormat( "$#,##0.00" );

            String interestRate = percent.format(annualInterestRate);
            String numOfYears = Integer.toString(numberOfYears);
            String loanAmnt = loan.format(loanAmount);

            String total = "Annual Interest Rate:\t" + interestRate + "\nNumber of Years:\t\t" + numOfYears + "\nLoan Amount:\t\t\t" + loanAmnt;

            return total;
        }
    }

My problem is with the getTotalPayment method. It can't access the monthlyPayment variable without me either declaring monthlyPayment as a field, like annualInterestRate, or passing it to the getTotalPayment method. The issue is, getTotalPayment is not allowed to have parameters, and we aren't allowed to have any more fields than the three she instructed us to have, which are the three you'll see declared in the beginning of the code. So, my question: is there a way to make the variable monthlyPayment accessible to getTotalPayment, without making monthlyPayment a field or giving getTotalPayment a parameter?

Answer 1

You have a spelling error in your getTotalPayment() method.

What your trying to do is call the method getmonthlyPayment() when you should be calling getMonthlyPayment().

Incase you missed the suttle difference in my answer you have a lowercase 'm' when you want an uppercase 'M'.

Im not entirety sure if this is your problem, but its the only syntax error my IDE is telling me.