如果 else 语句没有调用 isServiceCharge() 方法？

Question

我几乎完成了这个银行账户程序。我有一个calculateSavings()方法或calculateCheckings()方法的调用。如果currentBalance小于要求的minSavingsor minChecking，我有一个else语句来调用该isServiceCharge()方法来扣除费用。该程序没有给我错误，但如果用户输入的 acurrentBalance小于minChecking或所需的数量minSavings，JOptionPane则不会显示输出。输入仍然有效，但没有弹出输出。其他一切都可以正常工作，例如增加利息，但在服务费中扣除费用则不然。我怎样才能解决这个问题？主班package com.company;import javax.swing.*;public class Main{    public static void main(String[] args)    {        {            BankAccount myBank = new BankAccount();            myBank.calculateNewBalance();        }    }}

Answer 1

这是一个小问题

如果您看到此功能，您将帐户类型更改为'Savings' 或 'Checking'。

public void calculateNewBalance()

   {

    if (accountType.equals("S") || accountType.equals("s"))

    {

        accountType = "Savings";

        calculateSavingsBalance();

    } else if (accountType.equals("C") || accountType.equals("c"))

    {

        accountType = "Checking";

        calculateCheckingBalance();

    }

}

然而，您正在将 accountType 与'c' 或 's'进行比较

public void isServiceCharge()

{

    if(accountType.equals("s") || accountType.equals("S"))

    {

        double newBalance = currentBalance - 10.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

    else if(accountType.equals("c") || accountType.equals("C"))

    {

        double newBalance = currentBalance - 25.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

}

这就是它没有进入任何一个块的原因，因此，如果您将条件更改为以下语句

if(accountType.equals("Savings"))

else if(accountType.equals("Checking"))

它会按您的预期工作

Answer 2

你的代码中实际发生了什么，

public void calculateNewBalance()

{

    if (accountType.equals("S") || accountType.equals("s"))

    {

        accountType = "Savings";

        calculateSavingsBalance();

    } else if (accountType.equals("C") || accountType.equals("c"))

    {

        accountType = "Checking";

        calculateCheckingBalance();

    }

}

for s or S accountType = "Savings";

对于c 或 C accountType = "正在检查";

但有趣的是在isServiceCharge()方法中

public void isServiceCharge()

{

    if(accountType.equals("s") || accountType.equals("S"))

    {

        double newBalance = currentBalance - 10.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

    else if(accountType.equals("c") || accountType.equals("C"))

    {

        double newBalance = currentBalance - 25.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

}

你检查过

accountType.equals("s") || accountType.equals("S") //for savings

accountType.equals("C") || accountType.equals("c")// for checking

所以上述条件永远不会满足。

所以解决办法是：

public void isServiceCharge()

{

    if(accountType.equals("Savings"))

    {

        double newBalance = currentBalance - 10.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

    else if(accountType.equals("Checking"))

    {

        double newBalance = currentBalance - 25.0;

        JOptionPane.showMessageDialog(null, "Account Number: " + getAccountNumber() + "\nAccount Type: " + getAccountType() + "\nMinimum Balance: $" + getMinSavings()

                + "\nBalance Before Interest and Fees: $" + getCurrentBalance() + "\n\nNew Balance: $" + newBalance);

    }

}