Question

所以无论方法输入如何，我都会继续收到this.app.router...的答案。当我输入0个月，6储蓄金额和100利率时，它应该会给我0.05，但回复是608.81。我觉得它可能是我的0循环或我设置的参数搞乱它。我已经尝试了关于for循环的所有想法。这是代码：

for

Answer 1

您将以下变量传递给您的方法：

public static double compoundValueMethod(double savingAmount,
                                         double annualInterestRate,
                                         int NumberOfMonth)

注意但是在方法中使用静态变量numberOfMonth而不是传递的NumberOfMonth参数（Java中的变量名称区分大小写）。默认情况下，numberOfMonth初始化为0，因此未输入for循环，方法返回0.

您应该消除静态变量并仅使用局部变量。如果你首先做到了这一点，你会得到一个编译错误，这将使你更容易找到你的错误。

Answer 2

你不需要静态变量。更新代码如下

公共课FifthAssignment2 {

public static double compoundValueMethod(double savingAmount, double annualInterestRate, int numberOfMonth) {
    {
        DecimalFormat formatter = new DecimalFormat(".00");
        double sixthMonth = 0.0;
        double monthlyInterestRate = annualInterestRate / 12;

        if (savingAmount < 0)
            if (annualInterestRate < 0) {
                JOptionPane.showMessageDialog(null, "Error. Both of your values are negative!");
                System.exit(0);
            }

        if (savingAmount < 0) {
            JOptionPane.showMessageDialog(null, "Error. Your savings amount is negative!");
        }

        else if (annualInterestRate < 0) {
            JOptionPane.showMessageDialog(null, "Error. Your annual interest rate is negative!");
        }

        else {
            for (int i = 0; i < numberOfMonth; i++) {
                sixthMonth = ((savingAmount+sixthMonth) * (1 + monthlyInterestRate));
            }
        }
        return sixthMonth;
    }
}




public static void main(String[] args) {

    DecimalFormat formatter = new DecimalFormat(".00");

    int numberOfMonth;                                                  


    String NOM = JOptionPane.showInputDialog("How many months? ");
    numberOfMonth = Integer.parseInt(NOM);


    double savingAmount; 

    String SA = JOptionPane.showInputDialog("What is your savings amount? "); 

    savingAmount = Double.parseDouble(SA); 






    String AIR = JOptionPane.showInputDialog("What is the annual interest rate? "); // Window
    // pops
    // up

    double annualInterestRate;
    annualInterestRate = Double.parseDouble(AIR); 

    {
        JOptionPane.showMessageDialog(null, "Your total compounded value after 6 months is "
                + compoundValueMethod(savingAmount, annualInterestRate, numberOfMonth));
    }

}

}

Answer 3

使用NumberOfMonth代替numberOfMonth

for (int i = 0; i < NumberOfMonth; i++) {
                sixthMonth = ((savingAmount+sixthMonth) * (1 + monthlyInterestRate));
            }

或内部方法可以指定

numberOfMonth=NumberOfMonth;

为什么这个方法总是产生0作为其返回值？

3 个答案: