Thread: Help needed writing a program using JOptionPane

Write a Java program that lets the user enter the loan amount and loan period in number of years and
displays the monthly and total payments for each annual interest rate starting from 3.5% to 8% with an
increment of 0.25%. Below are the formulas that can be used to calculate monthlyPayment & totalPayment.

factor = 1/ 1+(annualInterestRate/1200)

monthlyPayment = loanAmount * (1 - factor) / (factor * (1 - Math.pow(factor, numOfYears * 12)))


totalPayment = monthlyPayment * 12 * numOfYears;

Originally Posted by copeg

And...what's the problem? What have you tried? Where are you stuck? Suggest you read the link in my signature for getting help

This is what I have so far and I obviously know it's not correct at all. This is my very first time writing something like this JOptionPane.

import javax.swing.JOptionPane;

public class Payment {

public static void main (String [] args) {

String numOfYears;
double annualInterestRate;
double loanAmount;
//String monthlyPayment;
//String totalPayment;


String loanAmountString = JOptionPane.showInputDialog (null,
"Please enter the loan amount:",
"Lab Assignment 1",
JOptionPane.QUESTION_MESSAGE);
double monthlyPayment = Double.parseDouble(loanAmountString);
double totalPayment = Double.parseDouble(loanAmountString);

numOfYears = JOptionPane.showInputDialog (null,
"Please enter the number of years:",
"Lab Assignment 1",
JOptionPane.QUESTION_MESSAGE);


//totalPayment = Double.parseDouble (monthlyPayment * 12 * numOfYears);


}

}