java - 将对象添加到对象数组

Question

目标:如果有空间可以添加，则将新的 Movie 对象添加到现有 Movie[] 中。

代码:

    // Create the new Movie object
    Movie movieToAdd = new Movie (newTitle, newYear);

    // Add it to the Array
    count = addMovie(movieList, movieToAdd, count);

方法代码:

    public static int addMovie (Movie[] movieArray, Movie addMe, int count)
{
    if (count != movieArray.length)
    {
        count++;
        movieArray[count] = addMe;
        System.out.println("Movie added successfully!");
    }
    else
    {
        System.out.println("Array size of " + movieArray.length + " is full. Could not add movie.");
    }


    return count;
}

问题:目前，当打印出 movieList 数组时，即使创建的 Movie 对象在外面打印得很好，新条目也会打印为 null。因此，我假设将 addMe 对象添加到数组中的最佳方法是创建在数组中初始化的第二个新 Movie 对象，并逐个构建它(因此 addMe 将保留在内存中，并且 addMe 的“副本”将被设置到数组中)。

这对我来说感觉不太有效(我讨厌额外的数据......)。有更好的方法吗？

注意:Movie 对象实际上有 10 个私有(private)数据成员。对于本练习，我只需要传入两个参数并为其余参数设置默认值。你可以想象为什么我不使用十个 GET 语句来构建这个数组并将额外的对象卡在内存中......

编辑:当前打印输出(部分):

    Menu options:
1.  Show all movies: 
2.  Show movies sorted - manual
3.  Show movies sorted - auto
4.  Show Movie by Index
5.  Search for movie Linearly
6.  Search for movie using Binary Search
7.  Add a movie
20. Quit 
Please choose an option from the menu: 1 to 20: 
7
Let's add the information for the new movie. Give me a Title and 4-digit Year, and I'll fill in the rest.
Title? 
Me
Year of Release? 
Please enter a valid 4 digit year: 1000 to 9999: 
1213
Movie added successfully!
Menu options:
1.  Show all movies: 
2.  Show movies sorted - manual
3.  Show movies sorted - auto
4.  Show Movie by Index
5.  Search for movie Linearly
6.  Search for movie using Binary Search
7.  Add a movie
20. Quit 
Please choose an option from the menu: 1 to 20:




25 | Les Vampires (1915)                   | Louis Feuillade                               | "Edouard Mathe, Marcel Levesque"                                                                                                                                                          | 1915 |   0 | http://www.imdb.com/title/tt0006206/          | http://www.guardian.co.uk/film/movie/117077/vampires                               | France       | Horror               | 175
null | 176
=============================================================================

更多编辑:构造函数和 setter 代码 - 所有这些都应该正常工作。

    public Movie (String t, int y)
{
//  passed in
    this.title = setTitle(t);
    this.year = setYear(y);

//  defaults
    this.ranking = 0;
    this.director = "No Director";
    this.actors = "No Actors";
    this.oscars = 0;
    this.linkIMDB = "No IMDB Link";
    this.linkGuardian = "No Guardian Link";
    this.country = "No Country";
    this.genre = "No Genre";    
}

    public String setTitle (String newTitle)
{       
    if (newTitle == null)
    {
        this.title = "No Title";
    }
    else
    {
        this.title = newTitle;
    }

    return this.title;
}

    public int setYear (int newYear)
{
    if (newYear >= 999 && newYear <=10000)
    {
        this.year = newYear;
    }
    else
    {
        newYear = 0000;
    }

    return this.year;
}

Answer 1

不清楚您在问什么，但这部分是不正确的:

count++;
movieArray[count] = addMe;

如果movieArray.length是10，count是9怎么办？然后它将通过 count != movieArray.length 检查，然后您将尝试分配索引 10 处的元素。使用后增量:

movieArray[count++] = addMe;