Question

JAVA: amortization table:

Hi, I have built this code and in one of my methods: printDetailsToConsole I would like it to print the first 3 payments and the last 3 payments if n is larger than 6 payments.

Please help!

Thank you!!

//start of program
import java.util.Scanner;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.lang.Math;
//345678901234567890123456789012345678901234567890123456789012345678901234567890
/**
* Write a description of class MortgageCalculator here.
*
* @author ()
* @version ()
*/
public class LoanAmortization
{   
/*
*
*/
public static void main(String [] args) {
//declarling necessary values
Scanner s = new Scanner(System.in);
PrintWriter outputStream = outputStream = null;

System.out.println("Hello! This is a loan calculator.");
System.out.println("It will calculate your monthly payments and"
+ " your payments towards your incurred interest and print it to a csv. file");
System.out.println("If you would like to continue please enter"
+ "'y' for yes or 'n' for no");
//try-catch statement
try {
outputStream = new PrintWriter
(new FileOutputStream("mortgagecalculator.csv"));   
}
catch (FileNotFoundException e) {
System.out.println("Error opening csv file");
System.exit(0);
}

char choice = s.next().charAt(0);   
//while loop loops until user enters n when given choice
while ((choice == 'y') || (choice == 'Y')) {
//capture input values from user
getAmortizationTableDetails(s,outputStream);

//ask user if calculate another mortgage
System.out.println("Would you like to enter another mortgage payment?");
System.out.println("Please enter [y] for yes or [n] for no.");

//call to testing method
//testingVariables
choice = s.next().charAt(0);
}
//closing scanner and PrintWriter
s.close();
outputStream.close();
}

/* Method printDetails formats results to 2 decimals and prints it
* to file.
* The loop will ensure that each result will be
* formatted in the way just described and print it to the file.
* The comma after the first statement will ensure that the file seperates
* the results and formats it in a table. It will be possible to open
* the file in Excel this way.
*
* @parameters:
* Scanner s
* PrintWriter outputStream
* int month[]
* double principal[]
* double monthlyPayment[]
* double interestPayment[]
* double remainingBalance[]
* int n
* no return statement
*/
public static void printDetails(Scanner s, PrintWriter outputStream,
int month[], double principal [], double monthlyPayment [],
double interestPayment [], double remainingBalance[], int n ){
outputStream.println
("Month, Principal, Monthly Payment, Interest Payment, Remaining Balance");
for (int i = 0; i < n; i++) {
//print to file
outputStream.print(month[i] + ", ");
outputStream.printf("%.2f,",principal [i]);
outputStream.printf("%.2f,",monthlyPayment[i]);
outputStream.printf("%.2f,",interestPayment[i]);
outputStream.printf("%.2f\n",remainingBalance[i]);
}
}

public static void printDetailsToConsole(Scanner s,
int month[], double principal [], double monthlyPayment [],
double interestPayment [], double remainingBalance[], int n ){
System.out.println
("Month, Principal, Monthly Payment, Interest Payment, Remaining Balance");
for (int i = 0; i < n; i++) {
//print to file
System.out.print(month[i] + ", ");
System.out.printf("%.2f,",principal [i]);
System.out.printf("%.2f,",monthlyPayment[i]);
System.out.printf("%.2f,",interestPayment[i]);
System.out.printf("%.2f\n",remainingBalance[i]);

if (n < 6) {
//
System.out.print(month[i] + ", ");
System.out.printf("%.2f,",principal [i]);
System.out.printf("%.2f,",monthlyPayment[i]);
System.out.printf("%.2f,",interestPayment[i]);
System.out.printf("%.2f\n",remainingBalance[i]);

}
else {
//printing the first 3 payments and the last 3 payments
  
System.out.print(month[i] + ", ");
System.out.printf("%.2f,",principal [i]);
System.out.printf("%.2f,",monthlyPayment[i]);
System.out.printf("%.2f,",interestPayment[i]);
System.out.printf("%.2f\n",remainingBalance[i]);
  
  
}

  
}
}

/*
*
*/
public static void getAmortizationTableDetails
(Scanner s, PrintWriter outputStream)
{
//asking user for input
System.out.println("Enter your loan amount.");
double loanAmount = s.nextDouble();
System.out.println("Enter your annual interest rate (in percent).");
double interestRate = s.nextDouble(); //in percent;
interestRate = interestRate / 100; //to convert to decimal
interestRate = interestRate/12;
System.out.println("Enter the term of your loan in years");
int termOfLoan = s.nextInt();
int n = termOfLoan * 12; //n = number of payments
int size = (int) (termOfLoan * 12); //size for array

//creating and declaring arrays
double principal [] = new double [size];
double monthlyPayment[] = new double [size];
double interestPayment[] = new double [size];
int month[] = new int [size];
double remainingBalance [] = new double [size];
double startingBalance = loanAmount;

for (int i = 0; i < n; i++) {
month[i] = i+1;
monthlyPayment[i] =
calculateMonthlyPayment(loanAmount, interestRate, n);

//calling method to fill interestPayment array
interestPayment[i] = calculateInterest(startingBalance, interestRate);
principal [i] = startingBalance;
startingBalance = startingBalance - (monthlyPayment[i] - interestPayment[i]);
remainingBalance[i] = startingBalance;
}
//call to method affordableCheck
affordableCheck(loanAmount, interestRate, n);

//call to method printDetails
printDetails
(s, outputStream, month, principal, monthlyPayment,
interestPayment, remainingBalance, n);
printDetailsToConsole
(s, month, principal, monthlyPayment,
interestPayment, remainingBalance, n);
}

/*
*
*/
public static void affordableCheck (double loanAmount, double interestRate, int n){
Scanner s = new Scanner(System.in);
System.out.println("If you would like to know if you can afford this loan"
+ " please enter your annual income.");
double income = s.nextDouble();
double annualPayment = (calculateMonthlyPayment(loanAmount, interestRate, n) * 12);
if (annualPayment > income) {
System.out.println("You won't be able to afford this loan.");
}
else {
System.out.println("Congratulations! You can afford this loan.");
}
}

/* Method calculateMonthlyPayment calculates the monthly payment of the loan
* for the user.
*   
* @parameters: double loanAmount
* double interestRate
* int n
* @return: double monthlyPayment
*/
public static double calculateMonthlyPayment(double loanAmount, double interestRate, int n) {
double monthlyPayment;
monthlyPayment = (loanAmount * (interestRate * (Math.pow((1 + interestRate),n))))/
((Math.pow((1 + interestRate), n)) - 1);

//returns solution for monthlyPayment
return monthlyPayment;
}

/*
*
*/
public static double calculateInterest(double startingBalance, double interestRate) {
double interestAmount;
interestAmount = startingBalance * interestRate;
return interestAmount;
}

/* testingVariables tests if methods used in program will
* return correct values.
*
* Method testingVariables tests if the calculation for the interest and the
* monthlyPayment produce the accurate output.
* no parameters
* no return statement
*/
public static void testingVariables() {
System.out.printf("The interest should be $10. %.2f \n" , calculateInterest(1000,0.01));
System.out.printf("The monthly payment should be $13.22. %.2f \n", calculateMonthlyPayment(1000, 0.1, 120));
}

}

Answer 1

//start of program

import java.util.Scanner;

import java.io.FileOutputStream;

import java.io.FileNotFoundException;

import java.io.PrintWriter;

import java.lang.Math;

//345678901234567890123456789012345678901234567890123456789012345678901234567890

/**

* Write a description of class MortgageCalculator here.

*

* @author ()

* @version ()

*/

public class LoanAmortization {

/*

*

*/

public static void main(String[] args) {

// declarling necessary values

Scanner s = new Scanner(System.in);

PrintWriter outputStream = outputStream = null;

System.out.println("Hello! This is a loan calculator.");

System.out.println("It will calculate your monthly payments and"

+ " your payments towards your incurred interest and print it to a csv. file");

System.out.println("If you would like to continue please enter" + "'y' for yes or 'n' for no");

// try-catch statement

try {

outputStream = new PrintWriter(new FileOutputStream("mortgagecalculator.csv"));

} catch (FileNotFoundException e) {

System.out.println("Error opening csv file");

System.exit(0);

}

char choice = s.next().charAt(0);

// while loop loops until user enters n when given choice

while ((choice == 'y') || (choice == 'Y')) {

// capture input values from user

getAmortizationTableDetails(s, outputStream);

// ask user if calculate another mortgage

System.out.println("Would you like to enter another mortgage payment?");

System.out.println("Please enter [y] for yes or [n] for no.");

// call to testing method

// testingVariables

choice = s.next().charAt(0);

}

// closing scanner and PrintWriter

s.close();

outputStream.close();

}

/*

* Method printDetails formats results to 2 decimals and prints it to file. The

* loop will ensure that each result will be formatted in the way just described

* and print it to the file. The comma after the first statement will ensure

* that the file seperates the results and formats it in a table. It will be

* possible to open the file in Excel this way.

*

* @parameters: Scanner s PrintWriter outputStream int month[] double

* principal[] double monthlyPayment[] double interestPayment[] double

* remainingBalance[] int n no return statement

*/

public static void printDetails(Scanner s, PrintWriter outputStream, int month[], double principal[],

double monthlyPayment[], double interestPayment[], double remainingBalance[], int n) {

outputStream.println("Month, Principal, Monthly Payment, Interest Payment, Remaining Balance");

for (int i = 0; i < n; i++) {

// print to file

outputStream.print(month[i] + ", ");

outputStream.printf("%.2f,", principal[i]);

outputStream.printf("%.2f,", monthlyPayment[i]);

outputStream.printf("%.2f,", interestPayment[i]);

outputStream.printf("%.2f\n", remainingBalance[i]);

}

}

public static void printDetailsToConsole(Scanner s, int month[], double principal[], double monthlyPayment[],

double interestPayment[], double remainingBalance[], int n) {

System.out.println("Month, Principal, Monthly Payment, Interest Payment, Remaining Balance");

if (n >= 6) {

for (int i = 0; i < 3; i++) {

// print to file

System.out.print(month[i] + ", ");

System.out.printf("%.2f,", principal[i]);

System.out.printf("%.2f,", monthlyPayment[i]);

System.out.printf("%.2f,", interestPayment[i]);

System.out.printf("%.2f\n", remainingBalance[i]);

}

for (int i = n-3; i<n; i++) {

// print to file

System.out.print(month[i] + ", ");

System.out.printf("%.2f,", principal[i]);

System.out.printf("%.2f,", monthlyPayment[i]);

System.out.printf("%.2f,", interestPayment[i]);

System.out.printf("%.2f\n", remainingBalance[i]);

}

} else {

for (int i = 0; i < n; i++) {

// print to file

System.out.print(month[i] + ", ");

System.out.printf("%.2f,", principal[i]);

System.out.printf("%.2f,", monthlyPayment[i]);

System.out.printf("%.2f,", interestPayment[i]);

System.out.printf("%.2f\n", remainingBalance[i]);

}

}

}

/*

*

*/

public static void getAmortizationTableDetails(Scanner s, PrintWriter outputStream) {

// asking user for input

System.out.println("Enter your loan amount.");

double loanAmount = s.nextDouble();

System.out.println("Enter your annual interest rate (in percent).");

double interestRate = s.nextDouble(); // in percent;

interestRate = interestRate / 100; // to convert to decimal

interestRate = interestRate / 12;

System.out.println("Enter the term of your loan in years");

int termOfLoan = s.nextInt();

int n = termOfLoan * 12; // n = number of payments

int size = (int) (termOfLoan * 12); // size for array

// creating and declaring arrays

double principal[] = new double[size];

double monthlyPayment[] = new double[size];

double interestPayment[] = new double[size];

int month[] = new int[size];

double remainingBalance[] = new double[size];

double startingBalance = loanAmount;

for (int i = 0; i < n; i++) {

month[i] = i + 1;

monthlyPayment[i] = calculateMonthlyPayment(loanAmount, interestRate, n);

// calling method to fill interestPayment array

interestPayment[i] = calculateInterest(startingBalance, interestRate);

principal[i] = startingBalance;

startingBalance = startingBalance - (monthlyPayment[i] - interestPayment[i]);

remainingBalance[i] = startingBalance;

}

// call to method affordableCheck

affordableCheck(loanAmount, interestRate, n);

// call to method printDetails

printDetails(s, outputStream, month, principal, monthlyPayment, interestPayment, remainingBalance, n);

printDetailsToConsole(s, month, principal, monthlyPayment, interestPayment, remainingBalance, n);

}

/*

*

*/

public static void affordableCheck(double loanAmount, double interestRate, int n) {

Scanner s = new Scanner(System.in);

System.out

.println("If you would like to know if you can afford this loan" + " please enter your annual income.");

double income = s.nextDouble();

double annualPayment = (calculateMonthlyPayment(loanAmount, interestRate, n) * 12);

if (annualPayment > income) {

System.out.println("You won't be able to afford this loan.");

} else {

System.out.println("Congratulations! You can afford this loan.");

}

}

/*

* Method calculateMonthlyPayment calculates the monthly payment of the loan for

* the user.

*

* @parameters: double loanAmount double interestRate int n

*

* @return: double monthlyPayment

*/

public static double calculateMonthlyPayment(double loanAmount, double interestRate, int n) {

double monthlyPayment;

monthlyPayment = (loanAmount * (interestRate * (Math.pow((1 + interestRate), n))))

/ ((Math.pow((1 + interestRate), n)) - 1);

// returns solution for monthlyPayment

return monthlyPayment;

}

/*

*

*/

public static double calculateInterest(double startingBalance, double interestRate) {

double interestAmount;

interestAmount = startingBalance * interestRate;

return interestAmount;

}

/*

* testingVariables tests if methods used in program will return correct values.

*

* Method testingVariables tests if the calculation for the interest and the

* monthlyPayment produce the accurate output. no parameters no return statement

*/

public static void testingVariables() {

System.out.printf("The interest should be $10. %.2f \n", calculateInterest(1000, 0.01));

System.out.printf("The monthly payment should be $13.22. %.2f \n", calculateMonthlyPayment(1000, 0.1, 120));

}

}

===============================================
See Code,Thanks and let me know if its fine


PLEASE COMMENT if there is any concern.

if (n 6) 86 87 for (int i-0; i<3; i++) I // print to file System.out.print (month[i] + ", ) System.out.printf("%.2f,", principal [i]); System.out.printf("%.2f,'', monthlyPayment [i]); System. out . printf("%.2f,", înterestPayment[i]); System.out.printf("%.2f\n", remainingBalance [i]); 89 90 91 92 93 94 95 96 97 98 for (inti n-1; i>-(n-3); i--) //print to file System.out.print (month[i] + ", "); System.out.printf("%.2f,", principal [i]); System.out.printf("%.2f,", monthlyPayment [i]); System.out.printf("%.2f,", înterestPayment[i]); System.out.printfc"%.2fNn", remainingBalance [i]); 100 101 102 103 104 105 106 107 108 109 110 } else i for (int i 0; i < n; i++) { // print to file System.out.print(monthCi]+ ", "); System.out.printf("%.2f,'', principa [i]); System.out.printf("%.2f,", monthlyPayment [i]); System.out.printf("%.2f,", interestPayment[i]); System.out.printf("%.2f\n", remainingBalance [i]); 112 113 114 115 116 118