3 个支票账户 2 个没有透支的客户的构造函数，但是不想透支的客户得到一个

Question

ChequeAccount class 扩展帐户 class。帐户 class 包含 ID、名称和余额属性。 ChequesAccount class 有 overdraftLimit、amtOverdrawn 和 transactionNo 以及 super(ID, name, balance) from Account。我在数组中创建了 3 个 chqAccount 对象并打印了它们的详细信息。 Ringo 已在他的 chq 帐户中选择退出透支功能，因此他需要单独的构造函数。然而，当我打印所有支票账户的详细信息时，他是唯一获得透支便利的人。麻烦你了

public class TestAccounts6
{
   private static ChequeAccount[] chqAccount = new ChequeAccount[5];
   private static int indexNo = 0;

   public static void main(String[] args)
   {
      ChequeAccount c1 = new ChequeAccount("S1111", "Paul", 1245.00, 0, 0, 0);
      ChequeAccount c2 = new ChequeAccount("S2222", "Ringo", 2500.00);
      ChequeAccount c3 = new ChequeAccount("S3333", "John", 1575.00, 0, 0, 0);
      chqAccount[0] = c1;
      chqAccount[1] = c2;
      chqAccount[2] = c3;
      indexNo = 3;
      System.out.printf("%-10s%-10s%-10s%-10s%-10s%-10s%n", "ID", "Name", "Balance",
                        "Overdraft", "Amount", "No of");
      System.out.printf("%-10s%-10s%-10s%-10s%-10s%-10s%n", "", "", "",
                        "Limit", "Overdrawn", "Transactions\n");
      for (int i = 0; i < indexNo; i++)
      {
         chqAccount[i].print();
      }

   }

}
public class ChequeAccount extends Account
{
   protected double overdraftLimit = 10000;
   protected double amtOverdrawn = 0;
   protected int transactionNo = 0;

   // constructor
   public ChequeAccount(String ID, String name, double balance,
                        double overdraftLimit, double amtOverdrawn,
                        int transactionNo)
   {
      super(ID, name, balance);
      this.overdraftLimit = overdraftLimit;
      this.amtOverdrawn = amtOverdrawn;
      this.transactionNo = transactionNo;
   }

   public ChequeAccount(String ID, String name, double balance)
   {
      super(ID, name, balance);
   }

   public void print()
   {

      System.out.printf("%-10s%-10s$%-9.2f$%-9.2f$%-9.2f%-10d%n", ID, name,
                        balance, overdraftLimit, amtOverdrawn, transactionNo);
   }

}
public class Account
{
   protected String ID;
   protected String name;
   protected double balance;

   // Constructor
   public Account(String ID, String name, double balance)
   {
      this.ID = ID;
      this.name = name;
      this.balance = balance;
   }

预期的 ringo 不会获得透支额度，而 John 和 Paul 会。与预期相反

Answer 1

它运行正常。因为

您已经创建了 3 个 chqAccount 对象

ChequeAccount c1 = new ChequeAccount("S1111", "Paul", 1245.00, 0, 0, 0);

ChequeAccount c2 = new ChequeAccount("S2222", "Ringo", 2500.00);

ChequeAccount c3 = new ChequeAccount("S3333", "John", 1575.00, 0, 0, 0);

当您尝试打印此对象的值时。它正在按以下方式打印。

ID Name Balance Overdraft Amount No of
Limit Overdrawn Transactions

S1111 Paul 45.00 [=12=].00 [=12=].00 0 S2222
Ringo 00.00 000.00 [=12=].00 0 S3333 John
75.00 [=12=].00 [=12=].00 0

当我们观察到上述情况并查看林戈的详细信息时。它的 Balance 为：$10000.00，因为您还没有为 Ringo 分配任何值。但在 ChequeAccount 中如下。

  protected double overdraftLimit = 10000;
  protected double amtOverdrawn = 0;
  protected int transactionNo = 0;

它有默认值。以便在打印时采用默认值。

Answer 2

这是代码的预期行为。

public class ChequeAccount extends Account
{
   protected double overdraftLimit = 10000;
   protected double amtOverdrawn = 0;
   protected int transactionNo = 0;
   ...
}

您已经为这些变量分配了默认值。当您为 Ringo 调用构造函数时，这些变量不会更新，因此，将使用您分配的默认值。

对于 Paul 和 John，您正在为这些变量分配新值（全为 0），因此它们将被打印出来。

ChequeAccount c1 = new ChequeAccount("S1111", "Paul", 1245.00, 10000, 0, 0);
ChequeAccount c2 = new ChequeAccount("S2222", "Ringo", 2500.00);
ChequeAccount c3 = new ChequeAccount("S3333", "John", 1575.00, 10000, 0, 0);

public class ChequeAccount extends Account
{
   protected double overdraftLimit = 0;
   protected double amtOverdrawn = 0;
   protected int transactionNo = 0;
   ...
}

使用上述更改修改您的代码现在将显示 Paul 和 John 的透支限额大于零，同时使 林戈的极限0.

3 个支票账户 2 个没有透支的客户的构造函数，但是不想透支的客户得到一个

3 cheque accounts 2 constructors for cust without overdraft but cust who does not want overdraft is getting one

java

inheritance

constructor

superclass