0

我想将多项选择题列表读入 Java 中的多维数组，文件格式为：Question,answer1,answer2,answer3,answer4,correctanswer。

一公里有多少米？,1,10,100,1000,4,彩虹童谣中没有哪个颜色？,蓝色,粉色,黑色,橙色,3 一个足球队有多少球员在球场上？ ,10,11,12,13,2

所以我希望数组采用 Question[][] 格式，如果 n 为 1，那么 Question[n][1] 将是 CSV 文件中的第一个问题，然后选择一个问题，我可以将 n 更改为无论我想要什么。

我不知道会有多少问题，它们会不断地从 CSV 文件中添加或删除，因此不会有静态数量。所以问题是如何以简单的方式从 CSV 文件中加载所有问题？

4

3 回答 3

0

最简单的方法是创建一个ArrayList或数组。这看起来很复杂，但使用这些ArrayList方法您不必担心问题的数量。

ArrayList<String[]> questions = new ArrayList<String[]>();
// Create the object to contain the questions.

Scanner s = new Scanner(new File("path to file"));
// Create a scanner object to go through each line in the file.

while(s.hasNextLine()) {
   // While lines still exist inside the file that haven't been loaded..
   questions.add(s.nextLine().split(","));
   // Load the array of values, splitting at the comma.
}

最后，您会得到一个ArrayList对象，其中每个条目都是 a String[]，其长度与每行上的标记数相同。

编辑

如对此答案的评论中所述，您可以简单地调用类中的toArray方法ArrayList，以获取多维数组。

于 2013-04-07T18:06:55.333 回答
0

您将需要设置一个嵌套的 for 循环来处理此问题：

for(i = 0; i < number_of_questions; i++)
{
    line_array = current_input_line.split(",")
    Questions[i] = line_array[0]
    for(j = 1; j < line_array.length; j++)
    {
        Questions[i][j] = line_array[j];
    }
}
于 2013-04-07T18:22:35.577 回答
0

当您必须为数据层次结构创建一个二维数组时，您可能应该为它创建一个合理的模型。

这是适合您的快速（且肮脏）模型（因打字速度而丢弃的设置器）：

问卷类：

/**
 * Facilitates an entire questionnaire
 */
public class Questionnaire extends ArrayList<Question> {

    /**
     * This questionnaire's name
     */
    private String name;

    /**
     * Creates a new questionnaire using the specified name
     * @param name  The name of this questionnaire
     */
    public Questionnaire(String name) {
        this.name = name;
    }

    /**
     * Returns the name of this questionnaire
     */
    public String getName() {
        return name;
    }
}

问题类：

/**
 * Facilitates a question and its answers
 */
public class Question extends ArrayList<Answer> {

    /**
     * The question's text
     */
    private String text;

    /**
     * Constructs a new question using the specified text
     * @param text  The question's text
     */
    public Question(String text) {
        this.text = test;
    }

    /**
     * Returns this question's text
     */
    public String getText() {
        return text;
    }
}

答题类：

/**
 * Facilitates an answer
 */
public class Answer {

    /**
     * The answer's text
     */
    private String text;

    /**
     * Whether or not this answer is correct
     */
    private boolean correct;

    /**
     * Constructs a new answer using the specified settings
     * @param text          The text of this answer
     * @param correct       Whether or not this answer is correct
     */
    public Answer(String text, boolean correct) {
        this.text = text;
        this.correct = correct;
    }

    /**
     * Returns this answer's text
     */
    public String getText() {
        return text;
    }

    /**
     * Whether or not this answer is correct
     */
    public boolean isCorrect() {
        return correct;
    }
}

它的用法如下：

// Create a new questionnaire
Questionnaire questionnaire = new Questionnaire("The awesome questionnaire");

// Create a question and add answers to it
Question question = new Question("How awesome is this questionnaire?");
question.add(new Answer("It's pretty awesome", false));
question.add(new Answer("It's really awesome", false));
question.add(new Answer("It's so awesome my mind blows off!", true));

// Add the question to the questionnaire
questionnaire.add(question);

迭代它非常容易：

// Iterate over the questions within the questionnaire
for(Question question : questionnaire) {
    // Print the question's text
    System.out.println(question.getText());

    // Go over each answer in this question
    for(Answer answer : question) {
        // Print the question's text
        System.out.println(answer.getText());
    }
}

您也可以只迭代其中的一部分：

// Iterate over the third to fifth question
for (int questionIndex = 2; questionIndex < 5; questionIndex ++) {
    // Get the current question
    Question question = questionnaire.get(questionIndex);

    // Iterate over all of the answers
    for (int answerIndex = 0; answerIndex < question.size(); answerIndex++) {
        // Get the current answer
        Answer answer = question.get(answerIndex);
    }
}

使用您描述的格式将文件读入模型可以通过以下方式完成：

// Create a new questionnaire
Questionnaire questionnaire = new Questionnaire("My awesome questionnaire");

// Lets scan the file and load it up to the questionnaire
Scanner scanner = new Scanner(new File("myfile.txt"));

// Read lines from that file and split it into tokens
String line, tokens[];
int tokenIndex;
while (scanner.hasNextLine() && (line = scanner.nextLine()) != null) {
    tokens = line.split(",");

    // Create the question taking the first token as its text
    Question question = new Question(tokens[0]);

    // Go over the tokens, from the first index to the one before last
    for (tokenIndex = 1; tokenIndex < tokens.length-1; tokenIndex++) {
        // Add the incorrect answer to the question
        question.add(new Answer(tokens[tokenIndex], false));
    }

    // Add the last question (correct one)
    question.add(new Answer(tokens[tokenIndex],true));
}

// Tada! questionnaire is now a complete questionnaire.
于 2013-04-07T18:24:36.133 回答