Question

I've created a mortgage calculator and the next step in my project is to include an array. I'm not very good at C++ as this is my first time taking a programming course. I was able to get this working but I'm confused as to where I could use an array. I was thinking of maybe using the person's credit score as an indication of what their interest rate could be for a HELOC. Something like this : int creditScore[3]={2.8, 3.0, 3.4} .

this is the code I'm working with right now, any help on how to include an array would be very much appreciated.

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main()
{
// Constant
const int
ONE = 1,
HUNDRED = 100,
NUMBER_OF_MONTHS = 12;

// Variables
int loanLength, creditScore;

float
Rate,
loanAmnt,
Payment,
totalPaid,
interestPaid;
//Program Title
cout << "Mortgage Calculator";
cout << endl << endl;
// Ask the user for loan amount, rate and mortgage years
cout << endl;
cout << "What is the Amount of the loan? ";
cin >> loanAmnt;
cout << "What is your credit score? ";
cin >> creditScore;
cout << "Mortgage Period (Years)? ";
cin >> loanLength;

{
if (creditScore >= 800)
{
Rate = 2.8;
cout << "Your interest rate is 2.8%" << endl;
}
else if (creditScore >= 780)
{
Rate = 3.0;
cout << "Your interest rate is 3.0%" << endl;
}
else if (creditScore >= 760)
{
Rate = 3.4;
cout << "Your interest rate is 3.4%" << endl;
}
else if (creditScore >= 740)
{
Rate = 3.8;
cout << "Your interest rate is 3.8%" << endl;
}
else if (creditScore >= 720)
{
Rate = 4.2;
cout << "Your interest rate is 4.2%" << endl;
}
else if (creditScore >= 700)
{
Rate = 4.6;
cout << "Your interest rate is 4.6%" << endl;
}
}

// Calculation
Rate /= NUMBER_OF_MONTHS;

Rate /= HUNDRED; // 4.25% == .0425

// Payment = [Rate * (1 + Rate)^(loanLength*12) / ((1 + Rate)^(loanLength*12) - 1)] * loanAmnt
Payment = ((Rate)*pow(ONE + (Rate), (loanLength * 12)) / (pow(ONE + (Rate), (loanLength * 12)) - ONE)) * loanAmnt;

Rate *= HUNDRED; // .0425 == 4.25

totalPaid = (loanLength * 12) * Payment;

interestPaid = ((loanLength * 12) * Payment) - loanAmnt;

// Display information to user
cout << setprecision(2) << fixed << right << endl;

cout << "Loan Amount: $";
cout << setw(10) << loanAmnt << endl;

cout << "Monthly Interest Rate: ";
cout << setw(10) << Rate << '%' << endl;

cout << "Number of Payments: ";
cout << setw(10) << (loanLength * 12) << endl;

cout << "Monthly Payment: $";
cout << setw(10) << Payment << endl;

cout << "Total Amount Paid: $";
cout << setw(10) << totalPaid << endl;

cout << "Interest Paid: $";
cout << setw(10) << interestPaid;

cout << endl << endl;

system("pause");
}

Answer 1

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

// Defines main function
int main()
{
// Constant
const int ONE = 1, HUNDRED = 100, NUMBER_OF_MONTHS = 12;

// Variables
int loanLength, creditScore;
float rate, loanAmnt, payment, totalPaid, interestPaid;
// Declares an float array for rate of interest
const float rateInterest [] = {2.8f, 3.0f, 3.4f, 3.8f, 4.2f, 4.6f, 4.9f};

// Displays program Title
cout << "Mortgage Calculator";
cout << endl << endl;
// Ask the user for loan amount, rate and mortgage years
cout << endl;
cout << "What is the Amount of the loan? ";
cin >> loanAmnt;
cout << "What is your credit score? ";
cin >> creditScore;
cout << "Mortgage Period (Years)? ";
cin >> loanLength;

// Checks if credit score is greater than or equals to 800
if (creditScore >= 800)
{
// Assigns the 0 index position data to rate
rate = rateInterest[0];
cout << "Your interest rate is "<<rate<<"%"<< endl;
}// End of if condition

// Otherwise checks if credit score is greater than or equals to 780
else if (creditScore >= 780)
{
// Assigns the 1 index position data to rate
rate = rateInterest[1];
cout << "Your interest rate is "<<rate<<"%"<< endl;
}// End of else if condition

// Otherwise checks if credit score is greater than or equals to 760
else if (creditScore >= 760)
{
// Assigns the 2 index position data to rate
rate = rateInterest[2];
cout << "Your interest rate is "<<rate<<"%"<<endl;
}// End of else if condition

// Otherwise checks if credit score is greater than or equals to 740
else if (creditScore >= 740)
{
// Assigns the 3 index position data to rate
rate = rateInterest[3];
cout << "Your interest rate is "<<rate<<"%"<< endl;
}// End of else if condition

// Otherwise checks if credit score is greater than or equals to 720
else if (creditScore >= 720)
{
// Assigns the 4 index position data to rate
rate = rateInterest[4];
cout << "Your interest rate is "<<rate<<"%"<< endl;
}// End of else if condition

// Otherwise checks if credit score is greater than or equals to 700
else if (creditScore >= 700)
{
// Assigns the 5 index position data to rate
rate = rateInterest[5];
cout << "Your interest rate is "<<rate<<"%"<< endl;
}// End of else if condition

// Otherwise credit score is less than 700
else
{
// Assigns the 6 index position data to rate
rate = rateInterest[6];
cout << "Your interest rate is " <<rate<<"%"<< endl;
}

// Calculation
rate /= NUMBER_OF_MONTHS;

rate /= HUNDRED; // 4.25% == .0425

// Payment = [Rate * (1 + Rate)^(loanLength*12) / ((1 + Rate)^(loanLength*12) - 1)] * loanAmnt
payment = ((rate)*pow(ONE + (rate), (loanLength * 12)) / (pow(ONE + (rate), (loanLength * 12)) - ONE)) * loanAmnt;

rate *= HUNDRED; // .0425 == 4.25

totalPaid = (loanLength * 12) * payment;

interestPaid = ((loanLength * 12) * payment) - loanAmnt;

// Display information to user
cout << setprecision(2) << fixed << right << endl;

cout << "Loan Amount: $";
cout << setw(10) << loanAmnt << endl;

cout << "Monthly Interest Rate: ";
cout << setw(10) << rate << '%' << endl;

cout << "Number of Payments: ";
cout << setw(10) << (loanLength * 12) << endl;

cout << "Monthly Payment: $";
cout << setw(10) << payment << endl;

cout << "Total Amount Paid: $";
cout << setw(10) << totalPaid << endl;

cout << "Interest Paid: $";
cout << setw(10) << interestPaid;
return 0;
}// End of main function

Sample Output:

Mortgage Calculator

What is the Amount of the loan? 5000
What is your credit score? 900
Mortgage Period (Years)? 2
Your interest rate is 2.8%

Loan Amount: $ 5000.00
Monthly Interest Rate: 0.23%
Number of Payments: 24
Monthly Payment: $ 214.47
Total Amount Paid: $ 5147.24
Interest Paid: $ 147.24