Solved
Java Mortgage Calculator
Posted on 2008-10-20
Hello experts, I am in Java class and I am having difficulties with my assignment. I have an assignment that I must create a calculator that can show the monthly payments on a 30 year mortgage. The principals are from $100000 -$200000 and shows the amount of interest between 6%-10% in 0.5% intervals. The output should be in a table format. Here is what our instructor is asking us to perform:
Programming problem 2: Mortgage monthly payment
The monthly payment on mortgage loan of L dollars, at a rate of interest r is given
by
Monthly payment = [ L(r/12)(1 + r/12) 12 n] / [(1 + r/12)12n - 1]
Where N is the number of years of mortgage. Write a program to find the monthly
payment for 30 years, for principals from $100,000 through $200,000(with increments
of $20,000) and interest rates of 6% through 10% (with increments of 0.5%). Print
monthly payment as a whole number (rounded off).
The output must be a neat table, similar to the following (your answers may be slightly
different because of rounding off).
Principal 6% 6.5% 7% 7.5% 8% 8.5% 9% 9.5% 10%
100000 600 632 665 699 733 768 804 840 877
120000 719 758 798 839 880 922 965 1009 1053
140000 & & & & & & & & &
160000 & & & & & & & & &
180000 & & & & & & & & &
200000 & & & & & & & & &
Hint: Use the following idea to compute (1 + r/12)
double temp = 1+r/12;
double temp1 = 1;
for (int i = 1; i<=12*N;i++)
{
temp1 = temp1*temp;
}
The final formula now becomes:
double mp = (L*(r/12)*temp1)/(temp1-1);
Here is what I have so far with my code:
import java.util.*;
class mortgageCalculator;
{
public static void main(String[]args)
{
double temp = 1+r/12;
double temp1 = 1;
double mp = (L*(r/12)*temp1)/(temp1-1);
for (int i = 1; i<=12*30;i++)
{
temp1 = temp1*temp;
}
for(temp1=.06;temp1<=.10;temp1++) // Is this the loop for the interest rate??
{
System.out.println("Monthly Payments" + mp);
}
for( int principal=100000;principal<=200000;principal++) // I am guessing there needs to be a loop to set the principal?
{
}
This table format looks like an array format. We haven't gotten into array's yet and I am pretty confused and unsure how to get started. I don't think this is supposed to be a GUI type of program. Any advice and guidance you could give me would be great. Thank you for your time.