Question

我正在尝试从文本文件中读取示例示例，但是，我的数组未为正确的字符串建立索引，并且我不知道如何解决它。输出返回空值。我可以得到一些指示吗？

public static void main(String[] args) throws FileNotFoundException {
    File file = new File("C:\\Users\\andre\\Documents\\NetBeansProjects\\ArrayExample2\\src\\Question1");
    Scanner fileScanner = new Scanner(file); // have to throw an exception

    String[] questions = new String[10];
    String[] answers = new String[4];
    String[][] choices = new String[10][4];//3 questions 4 possible answers

    for (int i = 0; i < 10; i++) {
        questions[i] = fileScanner.nextLine();
        System.out.println(questions[i]);
        for (int k = 0; k < 4; k++) {
            System.out.println(choices[i][k]);
        }

        String choicesInALine = fileScanner.nextLine();
        String[] choiceItems = choicesInALine.split("#");
        //transfer items with for loop

        for (int j = 0; j < choiceItems.length; j++) {
            choices[i][j] = choiceItems[j];
        }

        answers[i] = fileScanner.nextLine();
    }

    fileScanner.close();

    ...

//文本文件

Psychology and Science
85
By the 1920s a new definition of psychology had gained favor. Psychology was said to be the science of...
mind # consciousness # computers # behavior # philosophy

等等。

Answer 1

您有三个问题，但是您在循环中以questions数组形式输入了10次。另外，您还没有在choices数组中输入任何内容。您正在直接打印给出空值的choices数组：

for(int i = 0; i < 10; i++) {
    questions[i] = fileScanner.nextLine(); // questions array will contains questions and options
    System.out.println(questions[i]);
    for(int k = 0; k < 4; k++) {
        System.out.println(choices[i][k]); // You have taken no input in choices.
                                           //It will give null values
    }
}

您必须先在choices数组中输入内容，然后打印其值。

从文本中读取多维数组

1 个答案: