如何从两个不同的循环将数据放入构造函数

Question

我有一个家庭作业，要创建一个允许用户输入有关棋盘游戏集合的信息的应用程序。 用户输入的数据将通过 class 存储/访问。 我给出的步骤是创建名为 BoardGame 的 class，用于存储具有 8 个字段的（模拟或非数字）棋盘游戏集合。 然后我创建一个只存储前三个字段的构造函数。 然后，对于所有字段，我创建了单独的 get 和 set 方法，以及一个 toString 方法来打印所有字段的所有数据。 然后在 main 方法中有 3 个部分。 第 1 部分，创建一个名为 boardGames 的数组，其数组大小为 4（现在我只是将其设置为 1 进行测试）。 创建一个循环以仅获取前三条信息。 第 2 部分。在用户输入棋盘游戏的三个基本部分后，创建第二个循环以从用户那里获取剩余的五个信息。 第 3 部分。一旦用户输入并存储了所有剩余数据，创建第三个循环以使用 toString 方法（来自 BoardGame 类）为每个 object 打印数组中的所有数据。

我认为 BoardGame 中的所有内容都设置正确。 我也可以让第 1 步或第 2 步与第 3 步一起工作。问题是我不能让第 1 步和第 2 步同时工作。 数组要么有前 3 条信息，要么有最后 5 条信息

我尝试过制作多个构造函数。 我尝试了一堆可能都是菜鸟错误的东西XD

import java.util.Scanner;

public class Main {


    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);

        BoardGame[] boardGame = new BoardGame[1];

        // Loop for first three peices of info
        for (int i = 0; i < boardGame.length; i++) {

            String gameName, publisherName, yearPublished;

            System.out.print("What is the name of the board game? ");
            gameName = scnr.nextLine();

            System.out.print("Publisher name? ");
            publisherName = scnr.nextLine();

            System.out.print("Year published? ");
            yearPublished = scnr.nextLine();

            boardGame[i] = new BoardGame (gameName, publisherName, yearPublished);

        }

        // Loop for remaining peices of info
        for (int i = 0; i < boardGame.length; i++) {
            String genre;
            double price;
            int minPlayerNum, maxPlayerNum, playTime;

            System.out.print("How much does " + boardGame[i].getGameName() + " cost? ");
            price = scnr.nextDouble();

            System.out.print("What is the minimum number of players for " + boardGame[i].getGameName() + "? ");
            minPlayerNum = scnr.nextInt();

            System.out.print("What is the maximum number of players for " + boardGame[i].getGameName() + "? ");
            maxPlayerNum = scnr.nextInt();

            System.out.print("What is the game genre? ");
            scnr.nextLine();
            genre = scnr.nextLine();

            System.out.print("How long on average does it take to play " + boardGame[i].getGameName() + " (in minutes)? ");
            playTime = scnr.nextInt();

            boardGame[i] = new BoardGame (price, minPlayerNum, maxPlayerNum, genre, playTime);


        }
        for (int i = 0; i < boardGame.length; i++) {
            System.out.println(boardGame[i].toString());
            System.out.println();
        }

    }

}


public class BoardGame {
    // Fields
    private String gameName;
    private String publisherName;
    private String yearPublished;
    private double price;
    private int minPlayerNum;
    private int maxPlayerNum;
    private String genre;
    private int playTime;

    // Constructor 1
    public BoardGame(String gameName, String publisherName, String yearPublished) {
        this.gameName = gameName;
        this.publisherName = publisherName;
        this.yearPublished = yearPublished;
    }

    // Constructor 2
    public BoardGame(double price, int minPlayerNum, int maxPlayerNum, String genre, int playTime) {
        this.price = price;
        this.minPlayerNum = minPlayerNum;
        this.maxPlayerNum = maxPlayerNum;
        this.genre = genre;
        this.playTime = playTime;
    }

    // Get Methods
    public String getGameName() {
        return gameName;
    }

    public String getPublisherName() {
        return publisherName;
    }

    public String getYearPublished() {
        return yearPublished;
    }

    public double getPrice() {
        return price;
    }

    public int getMinPlayerNum() {
        return minPlayerNum;
    }

    public int getMaxPlayerNum() {
        return maxPlayerNum;
    }

    public String getGenre() {
        return genre;
    }

    public int getPlayTime() {
        return playTime;
    }

    // Set Methods
    public void setGameName(String gameName) {
        this.gameName = gameName;
    }

    public void setPublisherName(String publisherName) {
        this.publisherName = publisherName;
    }

    public void setYearPublished(String yearPublished) {
        this.yearPublished = yearPublished;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public void setMinPlayerNum(int minPlayerNum) {
        this.minPlayerNum = minPlayerNum;
    }

    public void setMaxPlayerNum(int maxPlayerNum) {
        this.maxPlayerNum = maxPlayerNum;
    }

    public void setGenre(String genre) {
        this.genre = genre;
    }

    public void setPlayTime(int playTime) {
        this.playTime = playTime;
    }
    // Prints the data FIX_ME if min and max number of players is the same, only print one number
    public String toString() {
        return "Game name: " + gameName + "\nPublisher Name: " + publisherName + 
                "\nYear Published: " + yearPublished + "\nPrice: " + price + 
                "\nMinimum number of players: " + minPlayerNum + "\nMaximum number of players: "
                + maxPlayerNum + "\ngenre: " + genre + "\nPlay time: " + playTime;
    }

}
`

根据我的设置方式，前三个没有分配值，或者最后 5 个没有。 它目前的设置方式是使前三个数据块 null。

Answer 1

在您的第二个循环中，不要像当前代码中那样用新的 BoardGame object 覆盖当前的BoardGame object：

boardGame[i] = new BoardGame (price, minPlayerNum, maxPlayerNum, genre, playTime);

您应该通过第一个循环检索已经存储在您的数组中的BoardGame ，并在其上调用您的设置器：

boardGame[i].setPrice(price);
boardGame[i].setMinPLayerNum(minPlayerNum);
//etc...

像这样，您不会覆盖/替换任何值，您只是向已经创建的 object 添加属性。