Java货币面额问题

Question

我正在尝试自学 Java，但在我拿到的书的两章中遇到了一点小问题 :P 这是其中一个练习中的一个:

“编写一个类，计算并显示输入的美元数到货币面额的转换——20s、10s、5s 和 1s。”

到目前为止，我将进行四个小时的阅读，从 0 编码知识开始，希望这听起来不是一个简单到难以回答的问题。我确信有一种更有效的方式来编写整个内容，但我的问题是如果用户回答"is"我如何终止整个内容或者如果他们回答“否”则继续修改版本？

如果你们能给我任何关于学习 Java 的建议或指导，我们将不胜感激!感谢您花时间阅读本文

import javax.swing.JOptionPane;
public class Dollars
{
    public static void main(String[] args)
    {
        String totalDollarsString;
        int totalDollars;
        totalDollarsString = JOptionPane.showInputDialog(null, "Enter amount to be     converted", "Denomination Conversion", JOptionPane.INFORMATION_MESSAGE);
    totalDollars = Integer.parseInt(totalDollarsString);
    int twenties = totalDollars / 20;
    int remainderTwenty = (totalDollars % 20);
    int tens = remainderTwenty / 10;
    int remainderTen = (totalDollars % 10);
    int fives = remainderTen / 5;
    int remainderFive = (totalDollars % 5);
    int ones = remainderFive / 1;
    JOptionPane.showMessageDialog(null, "Total Entered is $" + totalDollarsString + "\n" + "\nTwenty Dollar Bills: " + twenties + "\nTen Dollar Bills: " + tens + "\nFive Dollar Bills: " + fives + "\nOne Dollar Bills: " + ones);
    int selection;
    boolean isYes, isNo;
    selection = JOptionPane.showConfirmDialog(null,
        "Is this how you wanted the total broken down?", "Select an Option", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
    isYes = (selection == JOptionPane.YES_OPTION);
        JOptionPane.showMessageDialog(null, "You responded " + isYes + "\nThanks for your response!");
        isNo = (selection == JOptionPane.NO_OPTION);
        int twenties2 = totalDollars / 20;
        int tens2 = totalDollars / 10;
        int fives2 = totalDollars / 5;
        int ones2 = totalDollars / 1;
        JOptionPane.showMessageDialog(null, "Total Entered is $" + totalDollarsString + "\n" + "\nTwenty Dollar Bills: " + twenties2 + "\nTen Dollar Bills: " + tens2 + "\nFive Dollar Bills: " + fives2 + "\nOne Dollar Bills: " + ones2);
}
}

Answer 1

首先，您似乎真的不需要 isYes 和 isNo 这两个 boolean 值。基本上，您询问用户是否需要不同的解决方案，即一个真/假值(或者更确切地说:isNo 与 !isYes 相同，因为选项 Pane 将仅返回值 YES_OPTION 和 NO_OPTION 之一)。

接下来您要做的是转到“优化”版本如果用户表示第一个输出不是他想要的:

int selection = JOptionPane.showConfirmDialog(null,
        "Is this how you wanted the total broken down?", "Select an Option", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
if (selection == JOptionPane.NO_OPTION) {            
  int twenties2 = totalDollars / 20;
  int tens2 = totalDollars / 10;
  int fives2 = totalDollars / 5;
  int ones2 = totalDollars / 1;
  JOptionPane.showMessageDialog(null, "Total Entered is $" + totalDollarsString + "\n" + "\nTwenty Dollar Bills: " + twenties2 + "\nTen Dollar Bills: " + tens2 + "\nFive Dollar Bills: " + fives2 + "\nOne Dollar Bills: " + ones2);
}

如果用户选择"is"，您的主要方法无论如何都已完成，因此在这种情况下无需执行任何操作。