Question

任务是在创建银行账户时使用继承创建不同的类。然后我们存入，提取和报告余额。我有4个班级：

超类：BankAccount
子类：检查帐户
子类：储蓄账户
方法类：BankApp

BankAccount超类：

public class BankAccount {
    String firstName;
    String lastName;
    String ssn;
    protected float balance;
    float withdraw;
    float deposit;
    long accountNumber;

    BankAccount (){
    }

    BankAccount(String firstName, String lastName, String ssn, float balance){
        this.firstName = firstName;
        this.lastName = lastName;
        this.ssn = ssn;
        this.balance = balance;
    }

    long accountNumber() {
        long accountNumber = (long) Math.floor(Math.random() * 9000000000L) + 1000000000L;
        return accountNumber;
    }

    public void deposit(float amount) {
    balance = balance + amount;
    System.out.println(firstName + " " + lastName + " deposited $" + deposit + ". Current Balance $" + balance);

    }    

    public void withdraw(float amount) {
        if (balance >= withdraw) {
            balance = balance - amount;
            System.out.println(firstName + " " + lastName + " withdrew $" + withdraw + ". Current Balance $" + balance);
        }
        if (balance < withdraw) {
            System.out.println("Unable to withdraw " + amount + " for " + firstName + " " + lastName + " due to insufficient funds.");
        }
    }
}

检查帐户子类：

public class CheckingAccount extends BankAccount {

    float amtInterest;
    float applyInterest;
    String displayBalance;

    public CheckingAccount() {
    }

    public CheckingAccount(String firstName, String lastName, String ssn, float balance) {
        super(firstName, lastName, ssn, balance);
        System.out.println("Successfully created account for " + firstName + " " + lastName + " " + accountNumber);
        System.out.println(firstName + " " + lastName + ", Balance $" + balance);
    }    

    float applyInterest () {
       if (balance <= 10000) {
           balance = balance * 0.1f;  
           }
       if (balance > 10000) {
           balance = 1000 + (balance * 0.02f);
       }
       return balance;
    }

    float displayBalance() {
        return balance;
    }
}

我省略了SavingsAccount SubClass，因为我可以在这两个类的帮助下调整该类。

输出：

Successfully created account for Alin Parker 0 //Not displaying a random account number (1)
Alin Parker, Balance $1000.0
Successfully created account for Mary Jones 0
Mary Jones, Balance $500.0
Successfully created account for John Smith 0
John Smith, Balance $200.0
Alin Parker deposited $0.0. Current Balance $23000.0 //Deposit being calculated but displayed as 0 (2)
Mary Jones deposited $0.0. Current Balance $12500.0
Alin Parker withdrew $0.0. Current Balance $21000.0 //Withdrawal being calculated but displayed as 0 (3)
Mary Jones withdrew $0.0. Current Balance $11500.0
Alin Parker withdrew $0.0. Current Balance $-28580.0 //Should not show negative balance and only notice below (4)
Unable to withdraw 30000.0 for Alin Parker due to insufficient funds

我在输出中概述了我的上述问题：
1）随机化的10位数帐号显示为0
2）存款金额被扣除，但显示为0
3）扣除金额，但显示为0
4）应显示“资金不足”的陈述，而不是负余额 5）主要方法具有未执行的功能：

public class BankApp {
    public static void main(String[] args) {
        CheckingAccount acct1 = new CheckingAccount("Alin", "Parker", "123-45-6789", 1000.0f);

        CheckingAccount acct2 = new CheckingAccount("Mary", "Jones", "987-65-4321", 500.0f);

        SavingsAccount acct3 = new SavingsAccount("John", "Smith", "1233-45-6789", 200.0f);

        acct1.deposit(22000.00f);
        acct2.deposit(12000.00f);


        acct1.withdraw(2000.00f);
        acct2.withdraw(1000.00f);

        acct1.applyInterest(); //seems to skip
        acct2.applyInterest(); //seems to skip

        acct1.displayBalance(); //seems to skip
        acct2.displayBalance(); //seems to skip

        acct1.withdraw(30000.00f);
    }
}

提前感谢您的帮助

Answer 1

问题在于：

   public void withdraw(float amount) {
        if (balance >= withdraw) {  
            balance = balance - amount;
            System.out.println(firstName + " " + lastName + " withdrew $" + withdraw + ". Current Balance $" + balance);
        }
        if (balance < withdraw) {
            System.out.println("Unable to withdraw " + amount + " for " + firstName + " " + lastName + " due to insufficient funds.");
        }
    }

解决方案是：

public void withdraw(float amount) {
        if (balance >= amount) {
            balance = balance - amount;
            System.out.println(firstName + " " + lastName + " withdrew $" + amount + ". Current Balance $" + balance);
        }
        if (balance < amount) {
            System.out.println("Unable to withdraw " + amount + " for " + firstName + " " + lastName + " due to insufficient funds.");
        }
    }

JAVA银行账户申请

1 个答案: