Question

我有

System.out.printf("$%.2f\t $%.2f\n ",c.getDifference(),c.getAccValue());

但是c.getAccValue（）总是给我错误的输出，我不知道为什么。 getDifference（）的公式是getAccValue（） - principal，输出正确。

我每季度使用输入5000 8.25 5

CD课程：

package cd;

public class CD {
private int time; //in years, t
private double interest; //interest rate, r
private int principal; //principal, p
private String number;//number of times compounded, n

public CD(int time, double interest, int principal, String number){
this.time = time;
this.interest = interest;
this.principal = principal;
this.number = number;
}    

public int getTime(){
    return time;
}

public double getInterest(){
    return interest;
}

public int getPrincipal(){
    return principal;
}

public String getNumber(){
    return number;
}

public double getAccValue(){
    double A = 0;
    interest = interest/100;
         if( "daily".equals(number)) {
                A = Math.pow(1 + interest/365, 365*time) * principal;
         }
         else if ("weekly".equals(number)){
                A = Math.pow(1 + interest/52, 52*time) * principal;
         }
         else if ("monthly".equals(number)){
                A = Math.pow(1 + interest/12, 12*time) * principal;
         }
         else if ("quarterly".equals(number)){
                A = Math.pow(1 + interest/3, 3*time) * principal;
         }
         else if ("semiannually".equals(number)){
                A = Math.pow(1 + interest/2, 2*time) * principal;
         }
         else if ("annually".equals(number)){
                A = Math.pow(1 + interest/1, 1*time) * principal;
         } 
        return A;
    }

public double getDifference(){
    return getAccValue() - principal;
 }
}

CDTest课程：

package cd;

import java.util.Scanner;
import javax.swing.JOptionPane;


public class CDTest {

 /**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    // TODO code application logic here


    String input = JOptionPane.showInputDialog("Enter Principal value, "
            + "Interest rate, time (in years), " + " and number of months"
            + " compunded" + "\n(Separated by spaces)");
    Scanner in = new Scanner(input);
    int principal = in.nextInt();
    double interest = in.nextDouble();
    int time = in.nextInt();
    String number = in.next();

    CD c = new CD(time, interest, principal, number);

    System.out.println("Principal   " + "Interest   " + "Maturity   " + 
            "Number Compounded   " + "Amount Gained   " + 
            "Accumulated Value   " + "");
    System.out.println("=========   " + "========   " + "========   " 
            + "=================   " + "=============   " + 
            "=================   ");
    System.out.printf("  $" + c.getPrincipal() + "\t      "); 
    System.out.print(c.getInterest() + "%" + "\t  "); 
    System.out.print(c.getTime() + "\t      ");
    System.out.print(c.getNumber() +" \t");
    System.out.printf("$%.2f\t $%.2f\n ",c.getDifference(),c.getAccValue());          
    }  
}

感谢您的帮助

编辑：

当前输出为：

Principal   Interest   Maturity   Number Compounded   Amount Gained     
=========   ========   ========   =================   =============  
  $5000       8.25%       5         quarterly           $2510.99    
Accumulated Value 
=================   
$5020.66

预期输出为：

Principal   Interest   Maturity   Number Compounded   Amount Gained     
=========   ========   ========   =================   =============  
  $5000       8.25%       5         quarterly           $2510.99    
Accumulated Value 
=================   
$7510.99

Answer 1

.75 * running_total + new_value

您将乘以3.但一年中有四分之三。所以，我会仔细检查这个公式。

另外，你有这一行：

     else if ("quarterly".equals(number)){
            A = Math.pow(1 + interest/3, 3*time) * principal;

interest = interest/100;

中的

。这会永久性地改变利率。但是，getAccValue会调用getAccValue。因此，当计算差额时，它将利率除以100 - 然后当自己调用getDifference时，它再次将利率除以100 。所以现在你的利率微不足道，几乎没有任何钱。

printf给了我错误的输出

1 个答案: