Question

所以我在Java的高级继承中有一个任务，并且代码几乎被敲定了但是在完成它并使其实际显示输出时遇到了问题。该计划分为4个不同的部分，我将它们列在下面。

Account.java

public abstract class Account 
{
protected long accountNumber;
protected double accountBalance;
public long getAccountNumber()
{
    return accountNumber;
}
public double getAccountBalance()
{
    return accountBalance;
}
public void setAccountNumber(long number)
{
    number = accountNumber;
}
public void setAccountBalance(double balance)
{
    balance = accountBalance;
}
public void setUpAccount(long number, double  balance) //look up constructors
{
    number = accountNumber;
    balance = accountBalance;
}
public String toString()
{
    return "Account Number: " + accountNumber + " Account Balance: " + accountBalance;
}
public abstract double computeInterest(int intPeriod);
}

Checkings.java

public class Checking extends Account
{
public String toString()
{
    String info =  "Checking\nAccount Number: " + accountNumber + 
                                                   "\nAccount Balance: " + accountBalance ;
    return info;
}
public Checking(long number)
{
    number = accountNumber;
}
public double computeInterest(int intPeriod) 
{
    double total = ((accountBalance - 700) * .02) * 3;
    return total;
}
}

Savings.java

public class Savings extends Account
{
private double interestRate;
public double getInterest()
{
    return interestRate;
}
public void setInterest(double inter)
{
    inter = interestRate;
}
public String toString()
{
    String info = "Savings\nAccount Number: " + accountNumber + " \nAccount Balance: " 
                                                          + accountBalance + " \nInterest Rate: " + interestRate;
    return info;
}
public Savings(long number, double interest)
{
    number = accountNumber;
    interest = interestRate;
}
public double computeInterest(int intPeriod) 
{
    double total = Math.pow((1 + interestRate), intPeriod) * accountBalance - accountBalance;
    return total;   
}
}

AccountArray.java

public class AccountArray 
{   
    public static void main(String[] args)
    {
        Account[] refAccount = new Account[10];
        /*refAccount[0] = new Checking(100);
        refAccount[1] = new Checking(101);
        refAccount[2] = new Checking(102);
        refAccount[3] = new Checking(103);
        refAccount[4] = new Checking(104);
        refAccount[5] = new Savings(105, .02);
        refAccount[6] = new Savings(106, .02);
        refAccount[7] = new Savings(107, .02);
        refAccount[8] = new Savings(108, .02);
        refAccount[9] = new Savings(109, .02);

        refAccount[0].setAccountBalance(1000.0);
    refAccount[1].setAccountBalance(2000.0);
    refAccount[2].setAccountBalance(3000.0);
    refAccount[3].setAccountBalance(4000.0);
    refAccount[4].setAccountBalance(5000.0);
    refAccount[5].setAccountBalance(6000.0);
    refAccount[6].setAccountBalance(7000.0);
    refAccount[7].setAccountBalance(8000.0);
    refAccount[8].setAccountBalance(9000.0);
    refAccount[9].setAccountBalance(10000.0);*/
    for(int inc = 0; inc < 10; inc++ )
    {
        refAccount[0] = new Checking(100);
        refAccount[1] = new Checking(101);
        refAccount[2] = new Checking(102);
        refAccount[3] = new Checking(103);
        refAccount[4] = new Checking(104);
        refAccount[5] = new Savings(105, .02);
        refAccount[6] = new Savings(106, .02);
        refAccount[7] = new Savings(107, .02);
        refAccount[8] = new Savings(108, .02);
        refAccount[9] = new Savings(109, .02);

        refAccount[0].setAccountBalance(1000.0);
        refAccount[1].setAccountBalance(2000.0);
        refAccount[2].setAccountBalance(3000.0);
        refAccount[3].setAccountBalance(4000.0);
        refAccount[4].setAccountBalance(5000.0);
        refAccount[5].setAccountBalance(6000.0);
        refAccount[6].setAccountBalance(7000.0);
        refAccount[7].setAccountBalance(8000.0);
        refAccount[8].setAccountBalance(9000.0);
        refAccount[9].setAccountBalance(10000.0);
    }
    for(int ctr  = 0; ctr < 10; ctr++)
    {
        System.out.println(refAccount[ctr].toString());
    }
}

}

有什么东西我真的很想明白吗？这一切都很好，但输出只显示0而不是帐号，余额或利息。

任何帮助都会非常感激，因为我已经没时间了。

Answer 1

你所有的setter方法看起来都是错误的，你已经把它们当作......

public void setAccountNumber(long number)
{
    number = accountNumber;
}
public void setAccountBalance(double balance)
{
    balance = accountBalance;
}

你所做的只是设置参数值，它们应该是......

public void setAccountNumber(long number)
{
    accountNumber= number;
}
public void setAccountBalance(double balance)
{
    accountBalance= balance;
}

你可以确保我的参数最终不会发生这种情况

Answer 2

查看您的构造函数和设置器您可以反转变量属性

前

public void setAccountNumber(long number)
{
    number = accountNumber;
}

应该是

public void setAccountNumber(long number)
{
    accountNumber = number;
}

对于所有的setter和构造函数都是一样的

输出不显示任何内容

2 个答案: