貸款和利率程序C++

Question

我正在嘗試編寫一個程序，以便用戶輸入金額，利率和支付次數。

的代碼是假設輸出是這樣的：

Principal: 120000 
Interest rate: 10 
Number of payments: 12 

No.  Balance  Instalment  Interest Total payment 
---------------------------------------------------------------- 
    1  120000.00  10000.00  1000.00  11000.00 
    2  110000.00  10000.00   916.67  10916.67 
    3  100000.00  10000.00   833.33  10833.33 
    4  90000.00  10000.00   750.00  10750.00 
    5  80000.00  10000.00   666.67  10666.67 
    6  70000.00  10000.00   583.33  10583.33 
    7  60000.00  10000.00   500.00  10500.00 
    8  50000.00  10000.00   416.67  10416.67 
    9  40000.00  10000.00   333.33  10333.33 
10  30000.00  10000.00   250.00  10250.00 
11  20000.00  10000.00   166.67  10166.67 
12  10000.00  10000.00   83.33  10083.33 
---------------------------------------------------------------- 
         120000.00  6500.00  126500.00 

但我寫的代碼輸出以下：

Number of payments: 12 
No.  Balance  Instalment  Interest Total payment 
---------------------------------------------------------------- 
---------------------------------------------------------------- 
000Program ended with exit code: 0 

這裏是我到目前爲止的代碼。

#include <iostream> 

using namespace std; 

class Loan 
{ 
public: 
    Loan(double upphaed, double vextir, int afborganir); 
    void displaySchedule(); 

private: 
    void pay(int i); 
    double payments(); 
    double interest(int i); 
    double Balance(int i); 

    double sumOfInstalments; 
    double sumOfInterest; 
    double total; 
    double principal; 
    double interestRate; 
    int numOfPayments; 
}; 

Loan::Loan(double upphaed, double vextir, int afborganir) 
{ 
    upphaed = principal; 
    vextir = interestRate; 
    afborganir = numOfPayments; 
    sumOfInstalments = 0.0; 
    sumOfInterest = 0.0; 
    total = 0.0; 

} 

void Loan::pay(int i) 
{ 
    sumOfInstalments += payments(); 
    sumOfInterest += interest(i); 
    total += payments() + interest(i); 
} 

double Loan::payments() 
{ 
    return principal/numOfPayments; 
} 

double Loan::interest(int i) 
{ 
    return Balance(i) * (interestRate/12)/100; 
} 

double Loan::Balance(int i) 
{ 
    return principal - (i - 1) * payments(); 
} 

void readData(double& principal, double& interestRate, int& numOfPayments) 
{ 
    cout << "Principal: "; 
    cin >> principal; 
    cout << "Interest rate: "; 
    cin >> interestRate; 
    cout << "Number of payments: "; 
    cin >> numOfPayments; 
} 



void Loan::displaySchedule() 
{ 
    cout << "No.  Balance  Instalment  Interest Total payment" << endl; 
    cout << "----------------------------------------------------------------" << endl; 

    for (int i = 1; i <= numOfPayments; i++) 
    { 
     cout << i << "  " << Balance(i) << "  " << payments() << "  " << interest(i) << "  " << (payments() + interest(i)); 
     pay(i); 
    } 
    cout << "----------------------------------------------------------------" << endl; 
    cout << sumOfInstalments << sumOfInterest << total; 

} 
int main() 
{ 
    double amount, interestRate; 
    int numPayments; 

    readData(amount, interestRate, numPayments); 
    Loan myLoan(amount, interestRate, numPayments); 
    myLoan.displaySchedule(); 

    return 0; 
} 

Answer 1

你的構造函數是做事情的方式錯誤：

Loan::Loan(double upphaed, double vextir, int afborganir) 
{ 
    upphaed = principal; 
    vextir = interestRate; 
    afborganir = numOfPayments; 
    sumOfInstalments = 0.0; 
    sumOfInterest = 0.0; 
    total = 0.0; 
} 

相反的：

Loan::Loan(double upphaed, double vextir, int afborganir) 
{ 
    principal == upphaed; 
    interestRate = vextir; 
    numOfPayments = afborganir; 
    sumOfInstalments = 0.0; 
    sumOfInterest = 0.0; 
    total = 0.0; 
}