Completed: Mortgage Calculator

Author: avinashbest

Main.java

@@ -4,14 +4,35 @@
 import java.util.Scanner;
 
 public class Main {
+    final static byte MONTHS_IN_YEAR = 12;
+    final static byte PERCENT = 100;
 
     public static void main(String[] args) {
         int principal = (int) readNumber("Principal ($1K - $1M): ", 1000, 1_000_000);
         float annualInterest = (float) readNumber("Annual Interest Rate (1% - 30%): ", 1, 30);
         byte years = (byte) readNumber("Period (1 Years- 30 Years): ", 1, 30);
 
+        printMortgage(principal, annualInterest, years);
+
+        printPaymentSchedule(principal, annualInterest, years);
+    }
+
+    private static void printPaymentSchedule(int principal, float annualInterest, byte years) {
+        System.out.println();
+        System.out.println("PAYMENTS SCHEDULE:");
+        System.out.println("------------------");
+        for (short month = 1; month <= years * MONTHS_IN_YEAR; month++) {
+            double balance = calculateBalance(principal, annualInterest, years, month);
+            System.out.println(NumberFormat.getCurrencyInstance().format(balance));
+        }
+    }
+
+    private static void printMortgage(int principal, float annualInterest, byte years) {
+        System.out.println();
+        System.out.println("MORTGAGE");
+        System.out.println("--------");
         double mortgage = calculateMortgage(principal, annualInterest, years);
-        System.out.println("Mortgage: " + NumberFormat.getCurrencyInstance().format(mortgage));
+        System.out.println("Monthly Payments: " + NumberFormat.getCurrencyInstance().format(mortgage));
     }
 
     public static double readNumber(String prompt, double min, double max) {
@@ -28,10 +49,16 @@ public static double readNumber(String prompt, double min, double max) {
         return value;
     }
 
-    public static double calculateMortgage(int principal, float annualInterest, byte years) {
-        final byte MONTHS_IN_YEAR = 12;
-        final byte PERCENT = 100;
+    public static double calculateBalance(int principal, float annualInterest, byte years, short numberOfPaymentsMade) {
+        float monthlyInterest = annualInterest / PERCENT / MONTHS_IN_YEAR;
+        short numberOfPayments = (short) (years * MONTHS_IN_YEAR);
+
+        double balance = principal * (Math.pow(1 + monthlyInterest, numberOfPayments) - Math.pow(1 + monthlyInterest, numberOfPaymentsMade)) / (Math.pow(1 + monthlyInterest, numberOfPayments) - 1);
 
+        return balance;
+    }
+
+    public static double calculateMortgage(int principal, float annualInterest, byte years) {
         float monthlyInterest = annualInterest / PERCENT / MONTHS_IN_YEAR;
         short numberOfPayments = (short) (years * MONTHS_IN_YEAR);