如何使用多维数组列表? [英] how to work with Multidimensional arraylist?

问题描述

大家好，抱歉，我是 Java 的菜鸟，但我正在尝试做一些事情，我需要一个多维数组列表.它必须实现为以下代码:

Hey guys sorry i'm a noob at java but im trying to make something and i need a multidimensional array list. It must be implemented into the following code:

public static void OpenFile() {
 ArrayList<ArrayList<String>> array = new ArrayList<ArrayList<String>>();
    int retrival = chooser.showOpenDialog(null);
    if (retrival == JFileChooser.APPROVE_OPTION) {
        try (BufferedReader br = new BufferedReader(new FileReader(
                chooser.getSelectedFile()))) {
            String sCurrentLine;
            while ((sCurrentLine = br.readLine()) != null) {
                if (sCurrentLine.equals("")) {
                    continue;
                } else if (sCurrentLine.startsWith("Question")) {
                    System.out.println(sCurrentLine.split(":")[1]);
                    //add to [0] in array ArrayList
                } else if (sCurrentLine.startsWith("Answer")) {
                    System.out.println(sCurrentLine.split(":")[1]);
                    //add to [1] in array ArrayList
                } else if (sCurrentLine.startsWith("Category")) {
                    System.out.println(sCurrentLine.split(":")[1]);
                    //add to [2] in array ArrayList
                } else if (sCurrentLine.startsWith("Essay")) {
                    System.out.println(sCurrentLine.split(":")[1]);
                    //add to [3] in array ArrayList
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}

我拆分的字符串的所有 [1] 索引需要按以下顺序进入多维数组:问题、答案、类别、文章.
所以我目前使用的是一个普通的多维数组，但你不能轻易改变它的值.我希望我的多维数组列表看起来像这样:

All the [1] index's of the strings i split need to go into a multidimesional array in this order: question, answer, category, essay.
So i am currently using a normal multidimensional array but you cant change the values of it easily. What i want my multidimensional arraylist to look like is this:

多维数组列表

• [0]:问题(可能超过 100 个.)
• [1] 个答案(可能超过 100 个.)
• [2] 类别(可能超过 100 个.)
• [3] 论文(可能超过 100 篇.)

推荐答案

看起来像是一个 List of List 的作业.

Seems like an assignment with List of List.

这是伪代码.尝试实现休息.

Here is the psuedo code. Try to implement rest.

 ArrayList<ArrayList<String>> array = new ArrayList<ArrayList<String>>();

你要做的第一件事是获取 4 个新的 ArrayLists

First thing you have to do is take 4 fresh ArrayLists

 ArrayList<String> qtns= new ArrayList<String>>();
 ArrayList<String> answrs= new ArrayList<String>>();
--
--

将它们全部添加到主列表

Add all of them to main list

array.add(qtns);
--
--

然后现在像填充它们

     else if (sCurrentLine.startsWith("Question")) {
                        System.out.println(sCurrentLine.split(":")[1]);
                        //add to [0] in array ArrayList
                        array.get(0).add(sCurrentLine.split(":")[1]);//get first list(which is qtns list) and add to it.
     } else if (sCurrentLine.startsWith("Answer")) {
                    System.out.println(sCurrentLine.split(":")[1]);
                    //add to [1] in array ArrayList
 array.get(1).add(sCurrentLine.split(":")[1]);//get second list(which is answers list) and add to it.
                }
    -- -
    ---

这样最终您将获得一个包含数据的列表.

So that in the end you'll have a list of list which contains the data.

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