[ssonju]

Chose to go Live!

This post has been edited by ssonju: 17 April 2009 - 06:58 AM

[David W]

Edit:

code cleaned-up a little ... using some functions to make program more modular and using some input data validation to handle some invalid input

Shalom,
David
http://developers-he.../index.p...opic,127.0.html

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

// to make your updates easier ... place these here in global program scope
const int TABLE_YRS[] = {30, 15, 30, 40, 30, 7};
const double INT_RATES[] = {3.50, 6.25, 7.325, 5.50, 8.125, 10.25};

bool more() //  defaults to 'yes' ... i.e. must enter 'n' or 'N' for 'No'
{
    int reply;
    cout << "\nMore ... y/n ? " << flush;
    reply = cin.get();
    cin.sync(); // flush cin stream ...
    if(reply == 'n' || reply == 'N' )
        return false; // No more
    // else ... if you reach here ...
    return true; // Yes more ...
}

char showMenuGetOption() // uses global arrays TABLE_YRS[], INT_RATES[]
{
    char option ='0';
    // Prompts for Menu Selection ...
    for( int i = 0; i<6; ++i)
        cout << i+1<< ". " << setw(2) << TABLE_YRS[i] << " years at "
             << setw(5) << INT_RATES[i] << "%\n";

    // User's input for mortgage amount & menu option
    cout << "\nWhich loan option would you like? ";
    cin >> option;
    cin.sync();
    int T = int(option-'1'); // T is TABLE_YRS/AND INT_RATES array subscript
    cout << "You have chosen a ";
    char message[] = " year loan with an interest rate of ";
    switch (option)
    {
        case '1': cout << TABLE_YRS[T] << message << INT_RATES[T] << "%\n";
        break;         // You chose 30 years at 3.50%

        case '2': cout << TABLE_YRS[T] << message << INT_RATES[T] << "%\n";
        break;         // You chose 15 years at 6.25%

        case '3': cout << TABLE_YRS[T] << message << INT_RATES[T] << "%\n";
        break;         // You chose 30 years at 7.325%

        case '4': cout  << TABLE_YRS[T] << message << INT_RATES[T] << "%\n";
        break;         // You chose 40 years at 5.50%

        case '5': cout  << TABLE_YRS[T] << message << INT_RATES[T] << "%\n";
        break;         // You chose 30 years at 8.125%

        case '6': cout << TABLE_YRS[T] << " year loan with an interest rate of "
                       << INT_RATES[T] << "%" << endl;
        break;         // You chose 7 years at 10.25%

        default: cout  << "option NOT in the valid range 1..6\n"
                       << "Please choose a valid option. \n";
        return '0'; // Error flag value ...
    } // end switch ...

    return option;
}

void showLine( int Year, int forLoop, double mthAmtPd,
               double mthPrinPay, double mthPayment, double totMortAmt )
{
    cout << setw(4) << Year                     // Year
         << setw(6) << forLoop                  // Month
         << setw(14)<< mthAmtPd                 // interest
         << setw(15)<< mthPrinPay               // Principle
         << setw(16)<< mthPayment               // Payment
         << setw(17)<< totMortAmt               // Balance
         << endl;
}

double getDouble( char prompt[] )
{
    double mortgageAmount;
    for( ;; ) // loop forever until return with a good number ...
    {
        cout << prompt;
        cin >> mortgageAmount; // User's input for mortgage amount
        if( !cin.good() )
        {
            cin.clear();
            cin.sync();
            cout << "Error! Enter numbers only ...\n";
            continue;
        }
        cin.sync();
        return mortgageAmount;
    }
}



int main()
{
    // set to show 2 decimal places ...
    cout << setprecision(2) << fixed;
    
    do
    {
        char option = showMenuGetOption();
        if( option <'1' || option > '6' )
            continue; // jump to 'while( ... );'  at the end right now

        int T = int(option-'1');
        char prompt[] =
            "What is the amount you are borrowing (number without commas)? ";
        double princAmount = getDouble(prompt);
        // Amount you are borrowing ... (the principal)
           
        double monthlyInterestRate = INT_RATES[T]/1200;
        int totalMonths = TABLE_YRS[T]*12;

        // Mortgage Payment Calculator
        double mthPayment = princAmount * monthlyInterestRate /
                    (1 - pow((1 + monthlyInterestRate), -totalMonths));
        cout << "\nYour monthly mortgage payment is $" << mthPayment << endl << endl;

        cout << "Would you like to view an amortization table? (Y/N) ";
        char amortTable;
        cin >> amortTable; // User's input for mortgage amount
        cin.sync();
        
        // only if y or Y entered ... will the if ... block here get executed
        bool monthlyFlag = false; // declare here ... (needs this scope)
        if(amortTable == 'y' || amortTable == 'Y')
        {
            char view = '2'; // default to yearly on entry error ...
            cout << "\nWould you like to view monthly or yearly amortization? "
                 << "\n1. Monthly"      // Option 0 = 30 years at 3.50%
                 << "\n2. Yearly\n";    // Option 1 = 15 years at 6.25%
            cin >> view;
            cin.sync();
            if(view == '1') // Monthly Mortgage Amortization Routine
            {
                cout << "Monthly Routine" << endl;
                monthlyFlag = true;
            }
             // End if loop for Monthly Amortization routine
             

            int Year = 1;
            // for loop calculates & displays Balance, Principal Paid,
            // & interest Paid every 12 months until Balance is zero
            for(int forLoop = 1; forLoop <= totalMonths; forLoop++)
            {
                if( monthlyFlag && (forLoop)%12 == 1 )
                    cout << "Year Month   forInterest   forPrinciple   mnthlyPayment"
                         << "   presentBalance"
                         << endl;
                else if( forLoop%12 == 1 && Year%12 == 1 )
                    cout << "\nYear Month   forInterest   forPrinciple   mnthlyPayment"
                         << "   presentBalance"
                         << endl;
                // Code generates the current monthly interest and the amount for
                // the month to be applied to the principal
                double mthAmtIntPd = princAmount * monthlyInterestRate;
                double mthPrinPay = mthPayment - mthAmtIntPd;

                // Code checks to see if last payment ...
                // if so ... pay off prev. months balance + new interest ...

                if( forLoop == totalMonths )
                {
                    mthPayment = princAmount + mthAmtIntPd;
                    mthPrinPay = princAmount;
                    princAmount = 0;
                }
                else // Code generates the new principal or new mortgage amount
                {
                    princAmount = princAmount - mthPrinPay;
                }

                // Code creates a condition that will display the month
                // and mortgage balance once every 12 months
                if( !monthlyFlag )
                {
                    if( forLoop%12 == 0 )
                    {
                       showLine( Year, forLoop, mthAmtIntPd, mthPrinPay,
                                 mthPayment, princAmount );
                        ++Year;
                    }
                }
                else
                {
                    showLine( Year, forLoop, mthAmtIntPd, mthPrinPay,
                              mthPayment, princAmount );
                    if(forLoop%12 == 0)
                    {
                        ++Year;
                        cout << "\nPress 'Enter' to continue ... " << flush;
                        cin.sync();
                        cin.get();
                    } // end if
                } // end if/else
                
            } // End for loop for Yearly Mortgage Amortization routine

        } // End if loop for Amortization Table or not routine

        if( !monthlyFlag )
        {
            cout << "\nPress 'Enter' to continue ... " << flush;
            cin.sync();
            cin.get();
        }
        
    }while( more() );
} // End of Main

This post has been edited by David W: 17 April 2009 - 09:32 PM

[sbell1099]

Davids correct on that.It does need to be more modular.

Have a look thought it I spotted 2 mistakes I think.I CBA Looking what line and stuff