Java 填充对象数组时出现问题。结果总是空的

我创建了一个三级计划。在第三个类中，我应该用值“name”、“姓氏”、“code”和“age”填充数组。但是发生的事情是，我的数组总是“null”，我无法填充它。谢谢大家的帮助

头等舱：

import java.util.Scanner;

public class Main {
public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String name, surname;
    int code, age, i=0, min=150;        
    
    System.out.println("How many teachers do you want to enter information?");
    i=in.nextInt();     

            
    for(int j=0; j<i; j++) 
    {
        System.out.println("Enter the teacher's name");
        name=in.next();
        System.out.println("Enter the teacher's surname");
        surname=in.next();
        System.out.println("Enter the teacher's code");
        code=in.nextInt();
        System.out.println("Enter the teacher's age");
        age=in.nextInt();
        
        Teacher d = new Teacher(name, surname, code, age);
        System.out.println(d.getCode());
        System.out.println(d.getSurname());
        System.out.println(d.getAge());
        
        University c = new University(name, surname, code, age);
        min=c.MinimumAge(age, min);

    }
    
    System.out.println(min);

}
}

第三类（我将“0”作为填充数组的位置，以便进行测试）：

公立大学
{
私人教师[]数组=新教师[4]；；
公立大学（字符串名称、字符串姓氏、整数代码、整数年龄）
{
数组[0]=新教师（姓名、姓氏、代码、年龄）；
}
公共整数最小值（整数年龄，整数最小值）
{
如果（年龄未正确实施
大学班
。您可以通过以下方式实施：

class University {
    private int counter = 0;
    private final int MAX = 4;
    private Teacher[] array = new Teacher[MAX];

    public void addTeacher(Teacher teacher) {
        if (counter < MAX) {
            array[counter++] = teacher;
        }
    }

    public int minimumAge() {
        if (counter == 0) {
            return 0;
        }
        int min = array[0].getAge();
        for (int i = 1; i < counter; i++) {
            if (array[i].getAge() < min) {
                min = array[i].getAge();
            }
        }
        return min;
    }
}

运行示例：

How many teachers do you want to enter information?: 2
Enter the teacher's name: a
Enter the teacher's surname: b
Enter the teacher's code: 1
Enter the teacher's age: 23
Enter the teacher's name: x
Enter the teacher's surname: y
Enter the teacher's code: 2
Enter the teacher's age: 15
15

Teacher
的构造函数中不存在任何变量，例如
this.nome
@LiveandLetLive对不起，我从意大利语翻译了这个程序。现在我已经解决了。谢谢通知我。“我的向量总是“null”什么向量？@Andreas抱歉，“array”。谢谢。这是一个数组，创建时大小为4，第一个元素被赋值，所以其他3个元素将为空。这有什么奇怪的？此外，你怎么知道，因为你从来没有使用数组做任何事情？
class University {
    private int counter = 0;
    private final int MAX = 4;
    private Teacher[] array = new Teacher[MAX];

    public void addTeacher(Teacher teacher) {
        if (counter < MAX) {
            array[counter++] = teacher;
        }
    }

    public int minimumAge() {
        if (counter == 0) {
            return 0;
        }
        int min = array[0].getAge();
        for (int i = 1; i < counter; i++) {
            if (array[i].getAge() < min) {
                min = array[i].getAge();
            }
        }
        return min;
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String name, surname;
        int code, age, i = 0, min = 150;

        University university = new University();

        System.out.print("How many teachers do you want to enter information?: ");
        i = in.nextInt();

        for (int j = 0; j < i; j++) {
            System.out.print("Enter the teacher's name: ");
            name = in.next();
            System.out.print("Enter the teacher's surname: ");
            surname = in.next();
            System.out.print("Enter the teacher's code: ");
            code = in.nextInt();
            System.out.print("Enter the teacher's age: ");
            age = in.nextInt();

            university.addTeacher(new Teacher(name, surname, code, age));
        }

        System.out.println(university.minimumAge());
    }
}

How many teachers do you want to enter information?: 2
Enter the teacher's name: a
Enter the teacher's surname: b
Enter the teacher's code: 1
Enter the teacher's age: 23
Enter the teacher's name: x
Enter the teacher's surname: y
Enter the teacher's code: 2
Enter the teacher's age: 15
15