1

I already tried this:

public static void accountTypeSavings() {
    boolean b = true;
    while (b) {
        String startBalanceString = JOptionPane.showInputDialog(null, "Enter the starting balance in dollars without the dollar sign.");
        try {
            double startBalance = Double.parseDouble(startBalanceString);
            int accountID = 1;
            SavingsAccount accountID = new SavingsAccount(holder, startBalance);
            accountID += 1;
            b = false;
        }
        catch (final Exception ignored) {
            JOptionPane.showMessageDialog(null, "Only enter numbers, please.");
        }
    }
}

Creating an integer and setting the name of the savings account to the integer. But that's giving me the error "Duplicate local variable accountID".

When using my application, I want to get this:

SavingsAccount sa1 = new SavingsAccount(holder, startBalance);
SavingsAccount sa2 = new SavingsAccount(holder, startBalance);
SavingsAccount sa3 = new SavingsAccount(holder, startBalance);

The parameters are variables whose are already initialized!

I want to set the name of the new SavingsAccount to the accountID's value. So if I create a new instance of a SavingsAccount, I want my application to set it's name to sa1. And if I create another one after that, name it sa2, sa3, sa4, etc.

PS: Holder is a string, it contains the name of someone! It's not an integer!

I hope you understand what I mean!

4

4 回答 4

1 
int accountID = 1;
SavingsAccount accountID = new SavingsAccount(holder, startBalance);

您不能有 2 个具有相同名称的变量。

于 2013-07-17T09:55:01.663 回答
1

但是如果有第二个储蓄账户，我如何让应用程序创建一个名为 sa2 的储蓄账户，然后创建一个名为 sa3 等的储蓄账户？

声明一个全局 int，比如说 index。

private int index;

在构造函数中将其设置为 1：

this.index = 1;

每次有人创建储蓄账户时，增加指数。

SavingsAccount accountID = new SavingsAccount(holder + index++, startBalance);

这会将 的当前值添加index到holder字符串的末尾，然后增加 的值index。

编辑

好的，我明白你的意思了，但是变量不能以数字开头，或者只能以数字命名。相反，为什么不将这些帐户添加到一个array或一个List实现中呢？

List<SavingsAccount> accounts = new ArrayList<SavingsAccount>();
accounts.add(new SavingsAccount("Dave", something);
accounts.add(new SavingsAccount("Bill", somethingElse);

然后要获取每个帐户，您可以使用以下内容：

accounts.get(1);

注意：此列表基于 0。这意味着accounts.get(0);将获得第一项。

于 2013-07-17T09:59:00.240 回答
0

你需要的是一个列表。所以添加另一个静态变量 SavingAccountList

public static List<SavingsAccount> savingsAccountList = new ArrayList<SavingsAccount>();

您可以采用自动递增变量 m 并将其用作静态类变量：

public static int m=0;

public static void accountTypeSavings() {
        boolean b = true;

        holder="holderName"
        while (b) {
            String startBalanceString = JOptionPane.showInputDialog(null, "Enter the starting balance in dollars without the dollar sign.");
            try {
                double startBalance = Double.parseDouble(startBalanceString);
                SavingsAccount sa = new SavingsAccount(holder + m, startBalance);
                m++
                savingsAccountList.add(sa)
                b = false;
            }
            catch (final Exception ignored) {
                JOptionPane.showMessageDialog(null, "Only enter numbers, please.");
            }
        }
    }

您还需要导入 java.util.List。

于 2013-07-17T09:54:14.893 回答
0

您可能希望将节省的费用存储在您的方法之外的列表中。我建议一个领域：

private static List<SavingsAccount> savingsAccounts = new ArrayList<SavingsAccount>();

你的方法可能是这样的：

public static void accountTypeSavings() {
    boolean b = true;
    while (b) {
        String startBalanceString = JOptionPane.showInputDialog(null, "Enter the starting balance in dollars without the dollar sign.");
        try {
            double startBalance = Double.parseDouble(startBalanceString);
            savingAccounts.add(new SavingsAccount(holder, startBalance));
            b = false;
        }
        catch (final Exception ignored) {
            JOptionPane.showMessageDialog(null, "Only enter numbers, please.");
        }
    }
}

稍后您可以从列表中访问储蓄账户以修改其属性：

savingAccounts.get(0).addAmount(amount); // something like this to add money to the first account
于 2013-07-17T09:58:26.517 回答