Question

我正在努力使用此C ++程序来获取正确的每月付款金额。我认为公式不太正确，我认为我不太清楚，而且也弄乱了总回报的输出。我需要一些帮助来解决它。我在下面的代码中添加了到目前为止的内容：

#include <iostream>
#include <math.h>
using namespace std;

void mortgage::Mortgage() { // class object
    double loanAmount = 0;
    double annualInterestRate = 0;
    double totalYearsToRepay = 0;

  cout << "Enter the amount of the loan:";
  cin >> loanAmount;
  cout << "Enter annual interest rate in decimal term (example 0.075):";
  cin >> annualInterestRate;
  cout << "Enter the length of the loan in years:";
  cin >> totalYearsToRepay;

 cout << "Loan Amount: $" << fixed << loanAmount << endl;
 cout << "Annual Interest Rate: $" << fixed << annualInterestRate << endl;
 cout << "Total Years to Repay: $" << fixed << totalYearsToRepay << endl;

// Find monthly interest rate.
monthlyInterestRate=annualInterestRate /12;

// Find the total # of payments needed.
numberOfPayments = totalYearsToRepay* 12;

// Find power Factor.
 powerFactor = pow(1.0 + monthlyInterestRate, numberOfPayments);

// Find the monthly payment.
monthlyPayment= (loanAmount * monthlyInterestRate)/(1-pow(1 + monthlyInterestRate, totalYearsToRepay));

cout << "Monthly Payment: $" << fixed << annualInterestRate << endl;

    // Find the total pay back
    totalPayBack = (monthlyPayment) * (numberOfPayments);

cout << "Total Pay Back: $"  << fixed << totalPayBack << endl;
};

此代码应该获得的输出：

贷款金额：$ 50000.00
年利率：0.06250
还款年限：10
每月付款：$ 561.40
总回报：$ 67368.06

此代码的当前输出：

贷款金额：$ 50000.000000
年利率：0.062500美元
年还款额：$ 10.000000
每月付款：$ 0.062500
总回报：-599859.388428

Answer 1

您当前的问题是：

您不输出monthlyPayments。您输出annualInterestRate，而应该输出monthlyPayments。
您没有使用正确的公式来计算月付款。参见wrote。

对于本金（资本），c，定期（每月）利率，r，周期数（月），n，您的定期付款（每月付款），{ {1}}是：

p = ( c * r * ((1 + r)^n) ) / ( ((1 + r)^n) - 1 )是已经计算出的功率因数。因此，您可以在最终计算中使用它，以便于阅读。

Answer 2

您只需要更新这两行：

  // Find the monthly payment.
  monthlyPayment= (loanAmount * monthlyInterestRate)/(1-pow(1 + monthlyInterestRate, 
                   totalYearsToRepay));

  cout << "Monthly Payment: $" << fixed << annualInterestRate << endl;

成为

// Find the monthly payment.
double monthlyPayment= (loanAmount * (annualInterestRate / 12) * pow((1 + 
                        annualInterestRate / 12), (totalYearsToRepay * 12))) / (pow((1 
                        + annualInterestRate / 12), (totalYearsToRepay * 12)) - 1);

cout << "Monthly Payment: $" << monthlyPayment << endl;

使用正确的公式和正确的印刷方式。

C ++抵押计算器不正确的公式

2 个答案: