done mod4

src/main/java/com/h2/MortgageCalculator.java

@@ -0,0 +1,71 @@
+package com.h2;
+
+import java.text.DecimalFormat;
+
+public class MortgageCalculator {
+
+     private long loanAmount ;
+    private int termInYears  ;
+    private float annualRate ;
+    private double monthlyPayment;
+
+    public MortgageCalculator(long loanAmount, int termInYears, float annualRate)
+    {
+        this.loanAmount = loanAmount;
+        this.termInYears = termInYears;
+        this.annualRate = annualRate;
+    }
+
+    private int getNumberOfPayments() {
+        return this.termInYears * 12;
+    }
+
+    /*
+Inside `getMonthlyInterestRate()`, create a new `float` variable
+called `interestRate`, and assign to it the result of dividing
+`annualRate` by `100`. Then, divide the `interestRate` by `12`
+to calculate the monthly interest rate. Finally return the result of the calculation by replacing `0.0f`.
+ */
+    private float getMonthlyInterestRate() {
+        float interestRate = this.annualRate/100;
+        return interestRate / 12;
+    }
+
+    /*
+    P of type long, and assign it loanAmount
+r of type float, and initialize it to the return value of getMonthlyInterestRate()
+n of type int, and initialize the value by calling getNumberOfPayments()
+*/
+    public void calculateMonthlyPayment()
+    {
+        long P = this.loanAmount;
+        float r = getMonthlyInterestRate();
+        int n = getNumberOfPayments();
+        double M = P * (((r * Math.pow(1 + r, n))) / ((Math.pow((1 + r), n)) - 1));
+        this.monthlyPayment = M;
+    }
+
+    public String toString() {
+        DecimalFormat df = new DecimalFormat("####0.00");
+        return "monthlyPayment: " + df.format(monthlyPayment);
+    }
+
+    public static void main(String[] args) {
+        /*
+        A variable called loanAmount of type long. Initialize it by parsing the args[0] value (which
+        is of type String) to long using Long.parseLong().
+A variable called termInYears of type int and initialize by parsing args[1] using Integer.parseInt().
+A variable called annualRate of type float and initialize by calling Float.parseFloat().
+         */
+
+        long loanAmount = Long.parseLong(args[0]);
+        int termInYears = Integer.parseInt(args[1]);
+        float annualRate = Float.parseFloat(args[2]);
+
+        MortgageCalculator calculator = new MortgageCalculator(loanAmount, termInYears,annualRate);
+        calculator.calculateMonthlyPayment();
+
+        //System.out.println("Monthly Payment: " + calculator.toString());
+        System.out.println(calculator.toString());
+    }
+}