java 一个方法的银行帐户程序问题

Question

因此，对于硬件分配，我创建了一个 BankAccount class 和一个 Bank class。它基本上是完整的，除了我在创建一种添加月费的方法时遇到问题。我四处搜索，虽然我发现了大量类似的例子，但没有一个适合我的例子。

这是银行账户 class:

    public class BankAccount {

    String owner;
    int accountNumber;
    double balance;

    public BankAccount (String name, int acct){
        owner = name;
        accountNumber = acct;
    }

    public String toString() {
        String str = owner + " owns the account " + accountNumber + " with the balance of " + String.format("$%,.2f", balance);
        return str;
    }

    public double adjust(double amt) {
        balance = balance + amt;
        return balance;
    }

    public double getBalance() {
        return balance;
    }
}

这里是 Bank.java class:

import java.util.Arrays;

public class Bank {

    BankAccount[] bAcct;

    public Bank() {
        //Constructor - will create an array that can hold up to 10 BankAccount objects.
        bAcct = new BankAccount[10];
    }

    public void addAccount(BankAccount a) {
        //This method will take a BankAccount object as a param and place it in the next avail entry in array.
        for(int i = 0; i < bAcct.length; i++) {
            if (bAcct[i] == null){
                bAcct[i] = a;
                break;
            }
        }
    }

    public BankAccount getAccount(int index) {
        //will return a BankAccount object given an integer index value as a param
        return bAcct[index];
    }

    public void printAccounts() {
        //will display all of the BankAccount objects
        for (int i = 0; i < bAcct.length; i++) {
        if(bAcct[i] != null) {
            System.out.println(bAcct[i]);
            }
        }
    }

    public double monthlyFee(double f) {
        //will take a double value as a param and apply that value to every BankAccount object
        for (int i = 0; i < bAcct.length; i++){
            if(bAcct[i] !=null) {


            }
        }

    }
}

和测试class：

public class BankTest
{ 
  /*
   * test - set up a bank and add accounts
   */
  public static void main(String[] args)
  {
    // Code to test Bank and BankAccount classes
    int errors = 0;
    double fee = -2.95;

    System.out.println("\nCreate bank1");
    Bank bank1 = new Bank();
    System.out.println("\nOne account");
    BankAccount b1 = new BankAccount("Peter Chang", 3021);
    b1.adjust(1000.0);
    bank1.addAccount(b1);
    bank1.printAccounts();
    System.out.println("\nTwo accounts");
    BankAccount b2 = new BankAccount("Roddy Piper", 3049);
    b2.adjust(2000.0);
    bank1.addAccount(b2);
    bank1.printAccounts();
    System.out.println("\nThree accounts");
    BankAccount b3 = new BankAccount("Leeroy Jenkins", 4028);
    b3.adjust(3000.0);
    bank1.addAccount(b3);
    bank1.printAccounts();
    System.out.println("\nMonthly Fee");
    bank1.monthlyFee(fee);
    bank1.printAccounts();
    System.out.println("\nErrors:");

    if (bank1.getAccount(0).getBalance() != 997.05)
    {
      errors += 1;
      System.out.println("Balance for account at index 0 does not match 7.05");
    }
    if (bank1.getAccount(1).getBalance() != 1997.05)
    {
      errors += 1;
      System.out.println("Balance for account at index 1 does not match 97.05");
    }
    if (bank1.getAccount(2).getBalance() != 2997.05)
    {
      errors += 1;
      System.out.println("Balance for account at index 2 does not match 97.05");
    }
    if (errors == 0)
      System.out.println("No errors found!!!");
  }
}

我卡在 Bank.java class 中的 monthlyFee 方法上。任何帮助表示赞赏！提前致谢。

Answer 1

类似的东西：

public void monthlyFee(double f) {
        //will take a double value as a param and apply that value to every BankAccount object
        for (int i = 0; i < bAcct.length; i++){
            if(bAcct[i] !=null) {
                bAcct[i].adjust(f);
            }
        }
    }

从 monthlyFee 方法中删除了 return，因为您没有使用它并且不清楚您对它的期望 return。

顺便说一下，如果我是你，我会使用 List and ArrayList 而不是 Array，这样可以省去一些不必要的麻烦。

Answer 2

您可以简单地在循环中的每个帐户上使用您的 adjust 方法，并提供所提供的费用金额。

java 一个方法的银行帐户程序问题

java bankaccount program issue with a method

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