java - 字符串ArrayList返回空值

Question

我是java新手，正在做一些数组列表工作，在编译我的列表时，只返回空值而不是我输入的名称。

我不明白为什么会这样，所以如果有人可以建议/帮助我那就太好了。

这是我的主要代码

import java.util.*;

public class StudentData 
{
    public static void main(String[] args) 
    {
        Scanner in = new Scanner(System.in);
        ArrayList<Student> studentList = new ArrayList<Student>();
        String yesNo = "true";
        do
        {
            System.out.println("Enter student's name: ");
            String name = in.next();
            Student s = new Student();   
            studentList.add(s);
            String input;
            do
            {   
                System.out.println("Would you like to enter data for another student? Yes/No ");
                yesNo = in.next();
                }
            while (!yesNo.equalsIgnoreCase("YES") && !yesNo.equalsIgnoreCase("NO"));
            }   
        while (yesNo.equalsIgnoreCase("YES"));
            
        
        for(int i = 0; i < studentList.size(); i++)
        {
            System.out.println(studentList.get(i).getName());
            }
        }
    }

还有

class Student 
{
    private String studentName;
    
    public StudentData(String name)
    {
        setName(name);
    }
    public String getName()
    {
        return studentName;
        }
    public void setName(String name)
    {
        studentName = name;
        }
    }

Answer 1

您正在创建一名学生，但未设置名称:

            String name = in.next();
            Student s = new Student();   
            studentList.add(s);

尝试使用:

        String name = in.next();
        Student s = new Student();   
        s.setName(name);
        studentList.add(s);

同时替换您的构造函数。即:

public StudentData(String name){
        setName(name);
}

应该是

public Student(String name) {
        setName(name);
}

然后您将能够执行 Student s = new Student(name);