Question

这里总新手（感谢轴承）。我创建了一个抽象的父类：

public abstract class Account {


public double setInterestRate (double interestRate) {

    return this. interestRate = interestRate / 100;


public abstract void withdraw(double amount);


public void deposit(double amount) {
    if (amount < 0) { // amount is invalid: exception occurs
        throw new IllegalArgumentException("Error: Deposit cannot be a"
            + " negative value.");
    } else {
    this.deposit = amount;  
    balance = balance + amount;

    }
}

public void calculateBalance () {

        double interestTotal = balance * setInterestRate(interestRate);
        this.balance = balance + interestTotal;

}    
public double annualEarnings (double interest) {

  return this.interest =  1000 * setInterestRate(interestRate);

}

在子类中，我想将annualInterest变量作为参数传递给我在toString（）中调用的super.annualEarnings（annualInterest）方法：

public class CheckingAccount extends Account implements Overdraftable {

protected double annualInterest = 1.0;

@Override
public String toString() {

    return super.toString() + "\n"+ account + "\t\t" + deposit + "\t\t" 
        + withdrawAmt +"\t\t" + super.annualEarnings(annualInterest)+ "\t\t" + super.balance ;

}

我希望这种类型的打印输出：

=======================================
AccNo. Deposit  Withdraw Intr.  NewBal
=======================================
101    200.00   0.00    10.00  1210.00

每年1000美元的初始简单利息是10美元，即10.00（Intr。），剩下的只是200美元的存款，加上1000美元的初始，NewBal的10美元利息。

Answer 1

有些事情对我没有任何意义。在父类中，计算年度收入的方法是采用名为interest的变量，但随后将其完全丢弃，而使用局部变量interestRate。

public double annualEarnings (double interest) {

  return this.interest =  1000 * setInterestRate(interestRate);
}

我认为应该是

    public double annualEarnings (double interest) {

      return this.interest =  1000 * setInterestRate(interest);
    }

超级抽象类父级不接受子类参数

1 个答案: