Question

所以我有一个输出的变量ID

我只想获取第一个数字1并将其添加为student1.id 第二个数字为student2.id，依此类推。

当前，如果我打印出Student1.id，我会得到

我将如何处理？我尝试做一个for循环，但它说这是不可迭代的。

public class main { 
    /**
    * Reads a text file containing student data and uses this to populate the student objects
    *
    * @param filename Path to the student data file to be read
    * @return Whether the file was read successfully
    */
    public static boolean readFile(String filename) { File file = new File(filename);
    try {
    Scanner scanner = new Scanner(file);
    while(scanner.hasNextLine()){
    String[] words = scanner.nextLine().split(",");
    addStudent(words[0],words[1],words[2],words[3],words[4],words[5],words[6],words[7],words[8]); // TODO: Finish adding the parameters
    }
    scanner.close();
    } catch (FileNotFoundException e) { System.out.println("Failed to read file");
    }
    return true;
    }

static void addStudent(String id, String firstName, String lastName, String mathsMark1, String mathsMark2, String mathsMark3, String englishMark1, String englishMark2, String englishMark3) {

    Student student1 = new Student();
    Student student2 = new Student();
    Student student3 = new Student();
    Student student4 = new Student();
    Student student5 = new Student();

    student1.id = id;
    student1.firstname = firstName;
    student1.lastname = lastName;


      System.out.println(student1.id);



}

Answer 1

您正在使用split(",")。输入为1,2,3,4,5或将代码更改为split(" ")。

Answer 2

假设您的文件包含用逗号分隔的整数元素。我将创建一个List<Student>并将words存储到这样的每个列表元素

List<Student> students = new Arraylist<>();

for (int i = 0; i < words.length; i++) {
    Student s1 = new Student();
    s1.id = Intger.parseInt(words[i]); // since words is String[]
    students.add(s1)
}

在您的代码段中，您创建了5个Student对象，但仅使用第一个对象。

要输出，只需像这样使用for循环...

for (Student student: students) {
    System.out.println(student.id);
}

将新行上的字符串拆分为单独的变量

2 个答案: