Question

我是java的新手，我试图找出如何修改构造函数来创建BankAccount对象，当用户输入格式的年利率时，该对象存储每月利息？我无能为力，有什么想法吗？另外，BankAccount构造函数最初存储了BankAccount对象的实例字段的月利率，但年费率需要转换为月费率。那么如何切换它呢？

/**
 * BankAccount class
 * This class simulates a bank account.
 *
 * (Taken from "Starting Out with Java - Early Objects 
 * (Third Edition) by Tony Gaddis, 2008 by Pearson Educ.)
 * 
 */

public class BankAccount {
    public static void main(String[] args) {

    }
    private double balance;    // Account balance
    private double interestRate; // Interest rate
    private double interest;   // Interest earned

    /**
     * The constructor initializes the balance
     * and interestRate fields with the values
     * passed to startBalance and intRate. The
     * interest field is assigned to 0.0.
     */

    public BankAccount(double startBalance, double intRate)
    {
        balance = startBalance;
        interestRate = intRate;
        interest = 0.0; 
    } 

    /**
     * The deposit method adds the parameter
     * amount to the balance field.
     */

    public void deposit(double amount)
    {
        balance += amount;
    }

    /**
     * The withdraw method subtracts the 
     * parameter amount from the balance 
     * field.
     */

    public void withdraw(double amount)
    {
        balance -= amount;
    }

    /**
     * The addInterest method adds the interest 
     * for the month to the balance field.
     */

    public void addInterest()
    {
        interest = balance * interestRate;
        balance += interest;
    }

    /** 
     * The getBalance method returns the 
     * value in the balance field.
     */

    public double getBalance()
    {
        return balance;
    }

    /**
     * The getInterest method returns the
     * value in the interest field.
     */

    public double getInterest()
    {
        return interest;
    }
}

Answer 1

您可以在java中创建任意数量的构造函数，方法名称必须是类名

public BankAccount(double startBalance, double intRate,float interest )
{
balance = startBalance;
interestRate = intRate;
interest = 0.0; 
}

Answer 2

//以这种方式修改BankAccount构造函数。

public BankAccount(double startBalance, double intRate)
{
    balance = startBalance;
    interestRate = (intRate)/(12*100);
    interest = 0.0;
}

我如何修改构造函数？

2 个答案: