java - 根据 JOptionPane 的输入打印结果

Question

我是学生，正在努力完成家庭作业。现在我正在努力使用 JOptionPane 的输入来显示基于输入的结果。我的实验室有两个文件，CoinCounterTester.java 和 CoinCounter.java。两者都编译，但它应该打印美元总数和美分总数(教师指示)“输出应该在控制台窗口中，并且应该演示使用和转义序列”。我不确定测试器的任何部分是否正确，但我认为 JOptionPane 方法是正确的。我还认为我应该解析它们以将它们转换为整数形式，但是我不知道如何根据用户输入打印指定的美元数和剩余的美分数。谁能解释一下吗？

谢谢

编辑:好吧，答案似乎是正确的，但我对使用构造函数调用感到困惑。你会为构造函数调用的参数设置什么，我设置了

CoinCounter coinCounter = new CoinCounter(int quarters, int dimes, int nickels, int pennies); 

但是有七个错误

编辑2:

我现在还没有包含明智建议和输入的变量类型

CoinCounter coinCounter = new CoinCounter(quarters, dimes, nickels, pennies);

但我仍然收到 4 个错误(错误找不到符号):(。有人可以建议更正吗？

编辑 3:添加了 println 语句并将构造函数调用移至底部，但每当我运行程序时，我无法让文件打印美元数和美分数？!

import javax.swing.JOptionPane;

/**
 * A class to test the CoinCounter class
 */

public class CoinCounterTester
{
    /**
     * Tests methods of the CoinCounter class
     * @param args not used
     */



    public static void main(String[] args)
    {


        String quarter = JOptionPane.showInputDialog("Enter the quantity of quarters");
        int quarters = Integer.parseInt(quarter);

        String dime = JOptionPane.showInputDialog("Enter the quantity of dimes");
        int dimes = Integer.parseInt(dime);

        String nickel = JOptionPane.showInputDialog("Enter the quantity of nickels");
        int nickels = Integer.parseInt(nickel);

        String penny = JOptionPane.showInputDialog("Enter the quantity of pennies");
        int pennies = Integer.parseInt(penny);



        CoinCounter coinCounter = new CoinCounter(quarters, dimes, nickels, pennies);

        System.out.println(coinCounter.getDollars());
        System.out.println(coinCounter.getCents());






        System.exit(0);

    }
}




 /**
 * A CoinCounter has a specific number of cents.  It can provide the number of dollars and the
 * number of cents that it contains
 */
 public class CoinCounter
 {
    // constants
    //*** These are class constants so they need public static
    public static final int QUARTER_VALUE = 25;
    public static final int DIME_VALUE = 10;
    public static final int NICKEL_VALUE = 5;
    public static final int PENNY_VALUE = 1;
    public static final int PENNY_PER_DOLLAR_VALUE = 100;

    // instance field (one - holds the total number of cents EX:  8,534)
    private int total;

    /**
     * Constructs a CoinCounter object with a specified number of pennies,
     * nickels, dimes and quarters
     * @param quarterAmount the amount of quarters
     * @param dimeAmount the amount of dimes
     * @param nickelAmount the amount of nickels
     * @param pennyAmount the amount of pennies
     */
    public CoinCounter(int quarters, int dimes, int nickels, int pennies)
    {
        total = quarters * QUARTER_VALUE + nickels * NICKEL_VALUE + dimes * DIME_VALUE + pennies;



    }
    // add remaining methods as described

    /**
     * getDollars returns the number of dollars in the CoinCounter
     *  @return the number of dollars
    */
    public int getDollars()
    {
        int dollars = (int) total / PENNY_PER_DOLLAR_VALUE;
        return dollars;
    }
    /**
     * getCents returns the number the numbers of cents left over after the dollars are removed
     *  @return the number of cents left over
    */
    public int getCents()
    {
        int cents = total % PENNY_PER_DOLLAR_VALUE;
        return cents;
    }


 }

Answer 1

您正在寻找的是构造函数调用。你拥有所有的值(value)观。您只需要创建一个 CoinCounter 来为您计数。这样做的一个例子如下:

CoinCounter coinCounter = new CoinCounter(1, 2, 3, 4);

有了 CoinCounter 后，您可以调用它的方法，例如 coinCounter.getCents() 。您可以使用 System.out.println(<whatever you want to print>) 打印内容。这些应该是您需要完成的三件事。

编辑:关闭!仔细看看你是如何调用构造函数的以及我是如何做到的。你所做的是这样的:

CoinCounter coinCounter = new CoinCounter(int 1, int 2, int 3, int 4);

将其与我上面的示例进行比较。

只有在定义构造函数时才将变量类型放在那里，而不是在调用它时。