Java 构造函数不设置任何值

我开始了一个简单的项目，但遇到了一个问题。 主类

public static void main(String[] args){

    /*
• Ask the user how many new students will be added to the database.
• The user should be prompted to enter a name and year for each student.
• The student should have a unique 5-digit id, with the first being their grade level.
• The student should have several course options to choose from.
• Each course costs $600 to enroll.
• The student should be able to check their balance and pay tuition.
• The status of the student should show their name, id, courses, and balance.
     */
    Scanner input = new Scanner(System.in);
    Scanner n = new Scanner(System.in);
    int numberOfStudents=0,year;
    String firstName,lastName;

    System.out.println("How many students will attend this School? ");
    //input number of students
    System.out.print("Input : ");
    numberOfStudents = input.nextInt();
    //end
    //Input name and year for every student
    Student  students [] = new Student[numberOfStudents];
    Deposit deposit [] = new Deposit[numberOfStudents];

    for(int i = 0 ; i < numberOfStudents ;i ++){
        students[i]=new Student();
        deposit[i]=new Deposit(students[i]);
        //It consumes the /n character
        input.nextLine();
        //
        System.out.print("Insert First name : ");
        firstName=input.nextLine();
        students[i].setFirstName(firstName);

        System.out.print("Insert last name : ");
        lastName=input.nextLine();
        students[i].setLastName(lastName);

        System.out.print("Input year :");
        year=input.nextInt();
        students[i].setYear(year);
        //set cash test
        students[i].setCash(1000);
        //end
    }
    for(int j = 0 ; j < numberOfStudents ; j++){
        System.out.println("Student " + j + " First name " + students[j].getFirstName() + " has " + deposit[j].getBalance());
    }

    //end


}

当我调用Main

System.out.println（存款[j].getBalance（））时，它说它是0，但我把它放在存款类的构造函数中

此.balance
是否应该具有来自
student.getCash（）的值？
存款中的checkBalance方法为我提供了在主类student.getCash（）中调用它时所需的值。
在初始化存款的
现金之前，您正在使用
student
实例初始化存款，因此它将是
0
。初始化相应的
学生
后，移动
存款
的初始化，您应该可以：

for(int i = 0 ; i < numberOfStudents ;i ++){
    students[i]=new Student();
    //It consumes the /n character
    input.nextLine();
    //
    System.out.print("Insert First name : ");
    firstName=input.nextLine();
    students[i].setFirstName(firstName);

    System.out.print("Insert last name : ");
    lastName=input.nextLine();
    students[i].setLastName(lastName);

    System.out.print("Input year :");
    year=input.nextInt();
    students[i].setYear(year);
    //set cash test
    students[i].setCash(1000);
    //end

    deposit[i]=new Deposit(students[i]);
}

for（int i=0；i
该值是在您创建
存款
对象时设置的，该对象是在您创建新的
学生
对象之后立即设置的。此时，
Student
实例中的
cash
的值为零。你以后再设定。你可以这样做：

public int getBalance() {
    return this.student.getCash();
}

不是一次性设置
balance
成员，而是每次调用
Student
实例上的方法以获取更新的值。我并不是说这是最好的设计，但它似乎是您预期的结果。
您的存款构造函数在初始化任何学生字段之前调用getCash。
for(int i = 0 ; i < numberOfStudents ;i ++){
    students[i]=new Student();
    //It consumes the /n character
    input.nextLine();
    //
    System.out.print("Insert First name : ");
    firstName=input.nextLine();
    students[i].setFirstName(firstName);

    System.out.print("Insert last name : ");
    lastName=input.nextLine();
    students[i].setLastName(lastName);

    System.out.print("Input year :");
    year=input.nextInt();
    students[i].setYear(year);
    //set cash test
    students[i].setCash(1000);
    //end

    deposit[i]=new Deposit(students[i]);
}

public int getBalance() {
    return this.student.getCash();
}