Combining two programs to make one

Question

Is there an easy way for me to combine these two programs? What I am wanting to use an array for the different loans. Display the mortgage payment amount for each loan and then list the loan balance and interest paid for each payment over the term of the loan. Use loops to prevent lists from scrolling off the screen. Here are the two programs I have so far. Any guidance is appreciated.
import java.io.*;  // java input output package
import java.text.DecimalFormat; // allows placement of decimal
public class MonthlyPayments4e extends Thread //class header with "Thread" for sleep
public static void main(String[] args)
double Loan, NewBal, MIP;
   double Rate, MonthlyInterest, Payments; //double precision variables
   //assign values to variables
Loan= 200000; // loan amount
Rate = .0575; //interest rate
MonthlyInterest = Rate / 12; // interest for each month
     Payments = Loan * (MonthlyInterest / (1 - Math.pow(1+MonthlyInterest, -360))); //my formula
  DecimalFormat twoDigits = new DecimalFormat("$,000.00"); // declares decimal format
  MIP= (Loan * Rate) / 12;
  NewBal = Loan -(Payments-MIP);
  System.out.println("Monthly Payments Interest Paid This Payment Loan Balance");
     System.out.println();//my printout provides extra line
     System.out.print("  " + twoDigits.format(Payments)); //my printout
  System.out.print("\t\t\t" + twoDigits.format(MIP));//my printout
  System.out.println("\t\t\t" + twoDigits.format(NewBal));//my printout
    System.out.print("  " + twoDigits.format(Payments)); //my printout
  MIP=(NewBal*Rate)/12;
  System.out.print("\t\t\t" + twoDigits.format(MIP));//my printout
  NewBal=NewBal -(Payments-MIP);
  System.out.println("\t\t\t" + twoDigits.format(NewBal));//my printout
  System.out.print("  " + twoDigits.format(Payments)); //my printout
  while (NewBal > 1) //while loop to make computations continue until gets to $200000
  MIP=(NewBal*Rate)/12;
  System.out.print("\t\t\t" + twoDigits.format(MIP));//my printout
  NewBal=NewBal -(Payments-MIP);
  System.out.println("\t\t\t" + twoDigits.format(NewBal));//my printout
  System.out.print("  " + twoDigits.format(Payments)); //my printout
if (NewBal <100000) // tells when this is met to transition to sleep phase
  try
         Thread.sleep (500); //sleep phase needed per change request also states pause is 500 milliseconds
       catch (InterruptedException e)
import java.io.*;  // java input output package
import java.text.DecimalFormat;
public class MonthlyPayments5  //class header
public static void main(String[] args) //don't know if this is needed or not but here it is
double Loan;
   double Rate1,Rate2,Rate3, MonthlyInterest1,MonthlyInterest2,MonthlyInterest3,Payment1,Payment2,Payment3; //double precision variables
   //assign values to variables
   Loan= 200000; // loan amount
   Rate1 = 5.75;
   Rate2 = 5.5;
   Rate3 = 5.35;
   MonthlyInterest1 = (Rate1 / 100) / 12;
   MonthlyInterest2 = (Rate2 / 100) / 12;
   MonthlyInterest3 = (Rate3 / 100) / 12;
     Payment1 = Loan * (MonthlyInterest1 / (1 - Math.pow(1+MonthlyInterest1, -360))); //my formula
     Payment2 = Loan * (MonthlyInterest2 / (1 - Math.pow(1+MonthlyInterest2, -180))); //my formula
     Payment3 = Loan * (MonthlyInterest3 / (1 - Math.pow(1+MonthlyInterest3, -84))); //my formula
  DecimalFormat twoDigits = new DecimalFormat("000.00");
     System.out.println("\tYour Monthly Payments for 30 years are:\t $" + twoDigits.format(Payment1)); //my printout
     System.out.println("\tYour Monthly Payments for 15 years are:\t $" + twoDigits.format(Payment2)); //my printout
     System.out.println("\tYour Monthly Payments for 7 years are:\t $" + twoDigits.format(Payment3)); //my printout
 

Answer 1

Any guidance is appreciated. Here's some guidance:
ublic class MonthlyPayments4e extends Thread //class
header with "Thread" for sleepThere's no need for your class to extend Thread. If it truly needs to run in a separate thread, better to implement Runnable.
public static void main(String[] args)
{It's a common newbie mistake to put lots of code into main methods. After all, that's what you "run", right? Better to put that code into a class or instance method that you have a main method call. Other objects can get at it that way.
double Loan, NewBal, MIP;
double Rate, MonthlyInterest, Payments; //double
precision variablesLearn and follow the Sun Java coding standards:
http://java.sun.com/docs/codeconv/
This isn't VB.
The comment "// double precision variables" is totally, utterly useless. The fact that they're declared as double is more than sufficient. Useless comments like these just clutter up code.
//assign values to variablesMORE useless comments! Get rid of them. You've probably been taught that comments are good. I'm here to tell you that comments are bad. Write your code clearly enough and you won't need comments. Good choices for variable and method names and good refactoring are worth a million comments.
oan= 200000; // loan amount
Rate = .0575; //interest rate
MonthlyInterest = Rate / 12; // interest for each
monthThe principal, interest rate, and term length should all be input values to your method, not hardwired like this. If you're asked to change the rate or principal you have to recompile your code. Terrible.
Payments = Loan * (MonthlyInterest / (1 -
Math.pow(1+MonthlyInterest, -360))); //my formulaSeparate the calculation from the display.
DecimalFormat twoDigits = new
DecimalFormat("$,000.00"); // declares decimalUse a currency formatter. Your program should not care if it's USD or euros or some other currency. Let the default Locale figure out what the currency format should be.
format
MIP= (Loan * Rate) / 12;
NewBal = Loan -(Payments-MIP);
System.out.println("Monthly Payments Interest Paid
This Payment Loan Balance");Do the calculation in the method and let something else print out values.
System.out.println();//my printout provides extra
line
System.out.print(" " +
twoDigits.format(Payments)); //my printout
System.out.print("\t\t\t" +
twoDigits.format(MIP));//my printout
System.out.println("\t\t\t" +
twoDigits.format(NewBal));//my printout
System.out.print(" " +
twoDigits.format(Payments)); //my printout
MIP=(NewBal*Rate)/12;
System.out.print("\t\t\t" +
twoDigits.format(MIP));//my printout
NewBal=NewBal -(Payments-MIP);
System.out.println("\t\t\t" +
twoDigits.format(NewBal));//my printout
System.out.print(" " +
twoDigits.format(Payments)); //my printout
Why $200000? What if I wanted to calculate payments on $1M USD? Or 2B yen?
while (NewBal > 1) //while loop to make computations
continue until gets to $200000
MIP=(NewBal*Rate)/12;
System.out.print("\t\t\t" +
twoDigits.format(MIP));//my printout
NewBal=NewBal -(Payments-MIP);
System.out.println("\t\t\t" +
twoDigits.format(NewBal));//my printout
System.out.print(" " + twoDigits.format(Payments));
//my printout
if (NewBal <100000) // tells when this is met to
transition to sleep phase
try
Thread.sleep (500); //sleep phase needed per
change request also states pause is 500
millisecondsUgh - who told you to do this? Take it out.
catch (InterruptedException e)
import java.io.*;  // java input output package
import java.text.DecimalFormat;
ublic class MonthlyPayments5  //class header
public static void main(String[] args) //don't know
if this is needed or not but here it is
double Loan;
double Rate1,Rate2,Rate3,
MonthlyInterest1,MonthlyInterest2,MonthlyInterest3,Pa
ment1,Payment2,Payment3; //double precision
variables
//assign values to variables
Loan= 200000; // loan amount
Rate1 = 5.75;
Rate2 = 5.5;
Rate3 = 5.35;
MonthlyInterest1 = (Rate1 / 100) / 12;
MonthlyInterest2 = (Rate2 / 100) / 12;
MonthlyInterest3 = (Rate3 / 100) / 12;
Payment1 = Loan * (MonthlyInterest1 / (1 -
Math.pow(1+MonthlyInterest1, -360))); //my formula
Payment2 = Loan * (MonthlyInterest2 / (1 -
Math.pow(1+MonthlyInterest2, -180))); //my formula
Payment3 = Loan * (MonthlyInterest3 / (1 -
Math.pow(1+MonthlyInterest3, -84))); //my formula
DecimalFormat twoDigits = new
DecimalFormat("000.00");
System.out.println("\tYour Monthly Payments for
30 years are:\t $" + twoDigits.format(Payment1));
//my printout
System.out.println("\tYour Monthly Payments for
15 years are:\t $" + twoDigits.format(Payment2));
//my printout
System.out.println("\tYour Monthly Payments for 7
years are:\t $" + twoDigits.format(Payment3)); //my
printout
}See above for same comments on second messy method.
%