addPerson（添加到数组）方法不起作用，怎么了？

Question

我是一名从事项目的学生，我有一个方法接受一个人，将其添加到数组 (Admits[]) 并将数组写入文件。该方法当前不执行此操作，因为 numSoFar 值不会增加并且人员不会保存到数组中。 （或者我在我的测试类中犯了一个错误）我把这两个类的编码都放在下面，希望有人能指出我做错了什么的方向。由于这是一个学校项目，请尽量不要太具体，只是告诉我一些关于为什么我的编码可能不起作用的建议。我不想把别人的工作当作我自己的；我只需要一双新的眼睛来看看我没有的东西。

在我的数据库类中编码

    //adds a Person to the Database
public void addPerson(Person admit)
{
    for(int i = 0; i < numSoFar; i++)//i = -1 when admit's alpabetical spot in Database has been located
    {
        if((i == numSoFar-1) || (i == numSoFar))//there is no Person in this index, so this is the end of the database
        {
            Admits[i] = admit;
            numSoFar = numSoFar + 1;
        }
        else
        {
            if(Admits[i].getLN().compareTo(admit.getLN()) == -1)//last name comes before last name of Person at index i
            {
                Person current= Admits[i];
                Admits[i] = admit;
                while(i <= numSoFar)
                {
                    Person next = Admits[i+1];
                    Admits[i+1] = current;
                    current = next;
                    i++;
                }
                numSoFar++;
            }
            else
            {
                if(Admits[i].getLN().equalsIgnoreCase(admit.getLN()))//admit and Person at index i have the same last name
                {
                    if(Admits[i].getFN().compareTo(admit.getFN()) == -1)
                    {
                        Person current= Admits[i];
                        Admits[i] = admit;
                        while(i < numSoFar)
                        {
                            Person next = Admits[i+1];
                            Admits[i+1] = current;
                            current = next;
                            i++;
                        }
                        numSoFar++;
                    }
                    else
                    {
                        if(Admits[i].getFN().equalsIgnoreCase(admit.getFN())) //admit and Person at index i are the same person
                        {
                            Scanner in = new Scanner(System.in);
                            System.out.println("There is already a person with this name in the database.");
                            int c = 0;
                            while(c != 1 || c != 2)
                            {
                                System.out.println("If you would like to keep that person, enter '1', and if you would like to replace him/her with the person entered, enter 2.");
                                if(c == 2)
                                {
                                    Admits[i] = admit;  
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    this.writeToFile();
}

这是在我的测试人员中添加新人的代码（我在案例 1 后停止

    Person[] Admits = new Person[5000];
    Database dB = new Database(Admits);
    dB.fillFromFile();//fills array with info from text file
    Scanner in = new Scanner(System.in);
    String c = "0";
    System.out.println("Hello, and thank you for using the Notre Dame admitted students friend-finder");
    while(!c.equals("6")) //Menu for user to traverse, is exited when user enters a 6
    {
        System.out.println("Please pick the desired action from one of the options below and enter its number.");
        System.out.println("  1: Enter info for a new admitted student and check matches");
        System.out.println("  2: Change info for an admitted student already in the database");
        System.out.println("  3: Delete an admitted student from the database");
        System.out.println("  4: Log in as an admitted student to check matches");
        System.out.println("  5: View contact info for a certain person in the database");
        System.out.println("  6: Exit the program");
        c = in.next();
        switch(c)
        {
            case "1": //create new student and check matches
            System.out.println("Enter your first name:");
            String firstName = in.next();
            System.out.println("Enter your last name:");
            String lastName = in.next();
            System.out.println("Enter your gender:");
            String gen = in.next();
            Person p = new Person(lastName, firstName, gen);

            //String chracteristics
            System.out.println("Are you an a. introvert or b. extrovert? (enter a or b):");
            String traitIntroExtro = in.next();
            while(!(traitIntroExtro.equalsIgnoreCase("a") || traitIntroExtro.equalsIgnoreCase("b")))
            {
                System.out.println("Invalid choice.Please re-enter your choice:");
                traitIntroExtro = in.next();
            }
            if(traitIntroExtro.equalsIgnoreCase("a"))
            {
                p.setTraitIntroExtro("Introvert");
            }
            else
            {
                p.setTraitIntroExtro("Extrovert");
            }

上面的编码基本上是用不同的变量重复的，但是因为有很多我会切到案例1的末尾

    //facebook url to contact matches with
            System.out.println("Please enter the url of your facebook profile page:");
            String url = in.next();
            p.setFacebookUrl(url);
            dB.addPerson(p);
            p.fillMatches(dB);
            boolean first = dB.first();
            if(first == true)//the database only has one person in it
            {
                System.out.println("You are currently the only person in the database.");
            }
            else//the database has atleast one person in it
            {
                System.out.println("Your top 2 most compatible people currently in the data base are:");
                System.out.println(p.getMatches().getHead().getPerson() + ", who can be found at " + p.getMatches().getHead().getPerson().getFacebookUrl());
                if(dB.getNumSoFar() == 2)
                {
                    System.out.println("This is the only other person in the database.");
                }
                else
                {
                    System.out.println(p.getMatches().getHead().getNextNode().getPerson() + ", who can be found at " + p.getMatches().getHead().getNextNode().getPerson().getFacebookUrl());
                }

            }
            break;

Answer 1

让我们看一下您将 Person 添加到数组末尾的情况（就像还没有条目时一样）：

for(int i = 0; i < numSoFar; i++)
{
    if((i == numSoFar-1) || (i == numSoFar))
    {
        Admits[i] = admit;
        numSoFar = numSoFar + 1;
    }
    else
    { /* doesn't matter */ }
}

你的for循环永远不会退出：如果i = numSoFar-1，那么for循环的每次迭代都会将i和numSoFar都加1，因此i < numSoFar将永远是true。

另外，一条评论提到i 将是-1。除了通过减速和递增之外，我没有看到您分配i 的任何地方，那么它怎么可能是-1？

最后，一旦你有了一个工作版本，我建议你在Code Review Stack Exchange 上发布你的代码。我会在 Stack Overflow 上指出一些超出范围的非功能性问题（例如 cmets 中提到的 else { if (...) {...} } 与 else if (...) {...}）。