Question

我试图创建一个学生arraylist到一个课程类，以便当一个学生被添加时，arraylist增加。这是我到目前为止的代码：

import java.util.ArrayList;

/*
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/**
 *
 * @author Saj
 */
public class Course {
    private String courseName;
    private int noOfStudents;
    private String teacher;
    public static int instances = 0;

    //Getters
    public String getCourseName(){
        return this.courseName;
    }
    public int getNoOfStudents(){
        return this.noOfStudents;
    }
    public String getTeacher(){
        return this.teacher;
    }

    //Setters
    public void setCourseName(String courseName){
        this.courseName = courseName;
    }
    public void setNoOfStudents(int noOfStudents){
        this.noOfStudents = noOfStudents;
    }
    public void setTeacher(String teacher){
        this.teacher = teacher;
    }

    /**
     * Default constructor. Populates course name, number of students with defaults
     */
    public Course(){
        instances++;
        this.noOfStudents = 0;
        this.courseName = "Not Set";
        this.teacher = "Not Set";
    }

    /** 
     * Constructor with parameters 
     * @param noOfStudents integer
     * @param courseName String with the Course name
     * @param teacher String with the teacher
    */
    public Course(int noOfStudents, String courseName, String teacher){
        this.noOfStudents = noOfStudents;
        this.courseName = courseName;
        this.teacher = teacher;
    }

}

我不确定如何实现数组列表。有人能指出我正确的方向。

Answer 1

只需为您的班级添加属性

List<Student> students;

在构造函数中，初始化此列表：

students = new ArrayList<>();

创建将学生添加到列表的方法：

public boolean addStudent(Student stud) {
     if (stud == null || students.contains(stud)) {
        return false;
     }
     students.add(stud);
     return true;
}

另请查看https://docs.oracle.com/javase/8/docs/api/java/util/List.html以获取列表文档。问题是，你想在构造函数中添加学生吗？如果是这样，请将参数添加到构造函数

public Course(int noOfStudents, String courseName,
              String teacher, List<Student> students){
    this.noOfStudents = noOfStudents;
    this.courseName = courseName;
    this.teacher = teacher;
    this.students = new Arraylist<>(students);
}

创建学生arraylist以将学生添加到课程Java

1 个答案: