Question

我目前正在进行课堂作业，无法弄清楚为什么我会得到我得到的输出。编程问题是：

你操作几个热狗架。定义名为HotDogStand的类   它有一个用于热狗机架的ID号的实例变量和一个   这个展位当天销售了多少热狗的实例变量。   创建一个允许该类用户初始化的构造函数   两个变量。还要创建一个名为justSold的方法，该方法以   一个摊位已售出的热狗数量。这个想法是这个   每次看台卖热狗的时候都会调用方法   总计可以跟踪。添加另一个返回数字的方法   热狗卖了。

添加一个静态变量，用于跟踪销售的热狗总数   所有看台和一个返回此值的静态方法   变量

所以我的代码是：

public class HotDogStand {
    // instance variable declaration
    private int IDNumber;
    private int hotDogsSold = 0;
    private static int totalSold = 0;

    public HotDogStand(int ID, int sold) {
        IDNumber = ID;
        hotDogsSold = sold;
    }

    public int getID() {
        return IDNumber;
    }

    public void setID(int ID) {
        IDNumber = ID;
    }

    public void justSold() {
        if (hotDogsSold > 0) {
            hotDogsSold++;
        }
    }

    public int sold() {
        return hotDogsSold;
    }

    public static int getTotal() {
        return totalSold;
    }
}

我的测试课是：

public class HotDogTest {
    public static void main(String[] args) {
        HotDogStand stand1 = new HotDogStand(1, 11);
        HotDogStand stand2 = new HotDogStand(2, 17);
        HotDogStand stand3 = new HotDogStand(3, 6);

        stand1.getID();
        stand2.getID();
        stand3.getID();
        stand1.setID(1);
        stand2.setID(2);
        stand3.setID(3);
        stand1.justSold();
        stand2.justSold();
        stand3.justSold();
        stand1.justSold();
        stand1.justSold();
        stand1.justSold();
        stand3.justSold();

        stand1.getTotal();
        stand2.getTotal();
        stand3.getTotal();

        int grandTotal = stand1.getTotal() + stand2.getTotal() + stand3.getTotal();

        System.out.println("Stand " + stand1.getID() + " sold a total of " + stand1.getTotal() + " hotdogs.");
        System.out.println("Stand " + stand2.getID() + " sold a total of " + stand2.getTotal() + " hotdogs.");
        System.out.println("Stand " + stand3.getID() + " sold a total of " + stand3.getTotal() + " hotdogs.");

        System.out.println("The total amount of hotdogs sold by all the stands was " + grandTotal);
    }
}

我的输出是：

Stand 1共售出0个热狗 Stand 2共售出0个热狗 Stand 3共售出0个热狗所有看台销售的热狗总数为0

Answer 1

您永远不会更新totalSold字段。在justSold（）方法的内部增加，如果条件。

Answer 2

试试这个：

    public void justSold() {
    if (hotDogsSold > 0) {
        totalSold = hotDogsSold++;
    }

Answer 3

没有必要更改import re,urllib2 def find_words(each_func): i=0 wordsineach_func=[] while len(each_func) >0: i=i+1 word_found=longest_word(each_func) if len(word_found)>0: wordsineach_func.append(word_found) each_func=each_func.replace(word_found,"") # print i,word_found,each return wordsineach_func def longest_word(phrase): phrase_length=len(phrase) words_found=[];index=0 outerstring="" while index < phrase_length: outerstring=outerstring+phrase[index] index=index+1 if outerstring in words or outerstring.lower() in words: words_found.append(outerstring) if len(words_found) ==0: words_found.append(phrase) return max(words_found, key=len) data = urllib2.urlopen('https://s3.amazonaws.com/hr-testcases/479/assets/words.txt') words=[] for line in data: words.append(line.replace("\n","")) string="#honesthournow20" string=string.replace("#","") new_words=re.split(r'(\d+)',string) output=[] for each in new_words: each_words=find_words(each) for each_word in each_words: output.append(each_word) print output变量。 totalSold增加实例变量justsold，但hotDogsSold返回getTotal。

您需要一个方法totalSold，它返回实例变量getSold。

另一个问题是hotDogsSold是一个静态变量（它是一个类变量;它不依赖于类的任何单个实例，如热狗卖家1或2，而是整个热狗卖家模型）。因此，如果totalSold正确递增，您的总计将为每个人提供3倍的热狗销售量。

Java程序没有返回任何值

3 个答案: