包含 ArrayList 的对象答案

【问题标题】：Object that contains ArrayList包含 ArrayList 的对象
【发布时间】：2020-10-23 15:23:15
【问题描述】：

我正在做一个销售游戏的程序。现在在我的代码中，它只会显示客户写的最后一条评论，但我希望它包含游戏获得的所有评论的列表。我在想是否可以将ArrayList 作为变量而不是String 审查。下面是一个例子，说明它现在的样子。

public class Game {
    private String gameName;
    private int gamePrice;
    private String gameReviews;

    public Game(String gameName, int gamePrice, String gameReviews) {
        this.gameName = gameName;
        this.gamePrice = gamePrice;
        this.gameReviews = gameReviews;
    }
}

然后，如果我想创建一个对象来替换我拥有的旧对象，它会是什么样子？

public class Games {
    public static void main(String[] args) {
        String gameN = "Name";
        int gameP = 10;
        String gameR = "Review";
        Game game = new Game(gameN, gameP,gameR);
    }
}

【问题讨论】：

标签： java object arraylist

【解决方案1】：

可以使用 ArrayList 代替 String。

import java.util.ArrayList;

class Game {
    private String gameName;
    private int gamePrice;
    private ArrayList<String> gameReviews;

    public Game(String gameName, int gamePrice, ArrayList<String> gameReviews) {
        this.gameName = gameName;
        this.gamePrice = gamePrice;
        this.gameReviews = gameReviews;
    }
    public static void main(String[] args) {
        String gameN = "Name";
        int gameP = 10;
        ArrayList<String> gameReviews =  new ArrayList<String>();
        
        gameReviews.add("Review 1");
        gameReviews.add("Review 2");
        gameReviews.add("Review 3");
        gameReviews.add("Review 4");
        Game game = new Game(gameN, gameP,gameReviews);
  }

}

【讨论】：

工作得很好，谢谢。

【解决方案2】：

如果你的游戏和评论是一对多的关系，你的评论数据类型可以是List<String>

public class Game {
    private String gameName;
    private int gamePrice;
    private List<String> gameReviews;

    public Game(String gameName, int gamePrice, List<String> gameReviews) {
        this.gameName = gameName;
        this.gamePrice = gamePrice;
        this.gameReviews = gameReviews;
    }

    public Game(String gameName, int gamePrice) {
        this.gameName = gameName;
        this.gamePrice = gamePrice;
        this.gameReviews = new ArrayList<>();
    }

    public void addGameReview (String gameReview) {
        this.gameReviews.add(gameReview);
    }
}

如果你在初始化时有评论列表，你只需将它传递给构造函数：

List<String> reviews = new ArrayList<>();
Game game = new Game(gameN, gameP, reviews);

否则，您可以有一个构造函数，将 gameReviews 初始化为空的ArrayList，并在初始化后添加评论

Game game = new Game(gameN, gameP);

game.addGameReview("This is a review of Game ...");

【讨论】：