需要标识符是什么意思？

Question

我正在尝试制作一个程序，以跟踪热狗摊位以及它们出售了多少热狗，在制作该程序时，我有两个文件，这是第一个文件，它指向括号，我不确定这意味着什么。需要一个标识符。 这是代码

public class HotDogStand
{
    private String nameHotDogStand;
    private String IDnumber;
    private int hotDogsSold;

    public HotDogStand(String nameHotDogStand, String IDnumber, int hotDogsSold)
    {
        this.nameHotDogStand = nameHotDogStand;
        this.IDnumber = IDnumber;
        this.hotDogsSold = hotDogsSold;
    }

    public String getNameHotDogStand()
    {
        return nameHotDogStand;
    }

    public void setNameHotDogStand(String nameHotDogStand)
    {
        this.nameHotDogStand = nameHotDogStand;
    }

    public String getIDnumber()
    {
        return IDnumber;
    }

    public void setIDnumber(String IDnumber)
    {
        this.IDnumber = IDnumber;
    }

    public int getHotDogsSold()
    {
        return hotDogsSold;
    }

    public void setHotDogsSold(int HotDogsSold)
    {
        this.hotDogsSold = hotDogsSold;
    }

    public void SetJustSold(int hotDogsSold)
    {
        hotDogsSold++;
        totalHotDogsSold++;
    }

    public void showHotDogsSold(int hotDogsSold)
    {
        System.out.print("The number of hot dogs sold is: " + hotDogsSold);
    }

    private static int totalHotDogsSold;

    public  String showTotalHotDogsSold()
    {
        return ("The total number of hot dogs sold is: " + totalHotDogsSold);
    }

    public String toString()
    {
        return "The total number of hot dogs sold is: " + totalHotDogsSold;
    }

    public HotDogStand(HotDogStand otherHotDogStand)
    {
        nameHotDogStand = otherHotDogStand.nameHotDogStand;
        hotDogsSold = otherHotDogStand.hotDogsSold;
        IDnumber = otherHotDogStand.IDnumber;
    }

    public String toString()
    {
        return("Total sold =" + (one.getNumSold() + two.getNumSold() + 
                                 three.getNumSold()) + "\n");
    }

    one.SetJustSold();
    two.SetJustSold();
    three.SetJustSold();
}

第二个问题我不确定第二个文件。 我是否需要将“返回”置于公众下方但位于名称“ HotDogStand”上方，还是其他问题？

public class TheHotDogStands
{
    public static void main(String[]args)
    {
        HotDogStand one = new HotDogStand ("Bob's hotdog stand" , "0081"  , "5");
        HotDogStand two = new HotDogStand ("Chris's hotdog stand" , "4591" , "3");
        HotDogStand three = new HotDogStand ("Matt's hotdog stand" , "1171" , "10");


       System.out.println(one.getName + one.getID + one.getNumSold);
       System.out.println(two.getName + two.getID + two.getNumSold);
       System.out.println(three.getName + three.getID + three.getNumSold);
       System.out.println("Total sold for all stands = " + (one.getNumSold() + 
                                       two.getNumSold() + three.getNumSold()));

    }

    public one(one aOne)
    {
        nameHotDogStand = aNameHotDogStand;
        IDnumber = aIDnumber;
        hotDogsSold = aHotDogsSold;
    }
}

我对编程还是很陌生，可悲的是我们的书并不擅长于解释事物，我的老师说选择这本书是因为它适用于他们所教的两个班级，因此有没有好的网站提供指导，其中有一些很好的例子？ 我确实有时会找到一些，但它们似乎是从不同的来源和网站散布的。

感谢您提供任何信息。

Answer 1

在第一个方法中，您需要使用任何方法之外的这些行：

one.SetJustSold();
two.SetJustSold();
three.SetJustSold();

它们需要位于方法或静态初始化程序块中。

在第二个中，您从未声明one()的返回类型。