设置器Getter数组Java

Question

Can somebody help me with one little problem. I want to set for example 3 lectures to 1 student, but when i try this i can't set lectures.

student.setStudentLecture(lecture);
student.setStudentLecture(lecture1);

---

public class Student {
    private Lecture[] lecture;

    public void setStudentLecture(Lecture[] lecture) {
        this.lecture = lecture;
    }

    public Lecture[] getStudentLecture() {
        return lecture;
    }
}

Answer 1

You are using Array of Lecture objects and overwriting the same array with two different array references. Hence, it is not working. Use the below code:

    public class Student {
    private Lecture[] lecture;

    public void setStudentLecture(Lecture[] lecture) {
        this.lecture = lecture;
    }

    public Lecture[] getStudentLecture() {
        return lecture;
    }

    public static void main(String[] args) {
        Student student = new Student();
        Lecture[] lectures = new Lecture[3];
        lectures[0] = new Lecture("Physics");
        lectures[1] = new Lecture("Mathematics");
        lectures[2] = new Lecture("Chemistry");

        student.setStudentLecture(lectures);

        Lecture[] lectures1 = student.getStudentLecture();
        for (int i = 0; i <lectures1.length; ++i) {
            System.out.println(lectures1[i].getName());
        }
    }
}

public class Lecture {
    private String name;
    public Lecture(String name) {
        this.name = name;
    }

    public String getName(){
        return name;
    }
}

Answer 2

As you setter is also array, you can create the Array of Lecture and set it to Student.

sample:-

Student student = new Student();
Lecture lecture = new Lecture();
Lecture lecture1 = new Lecture();
Lecture[] lectureArr = new Lecture[]{lecture, lecture1};
student.setStudentLecture(lectureArr);

And also you have studentLecture as array, then why you want to assign different array twice, you can combine both array and assign it.