用对象动态填充 ArrayList

Question

我有摘要 class Human，它由其他两个 classes Student 和 Worker 扩展。我正在尝试填写两个数组列表。 Student 类型的 ArrayList 和 Worker 类型的 ArrayList 是动态的。

public abstract class Human {

private String fName = null;
private String lName = null;

public String getfName() {
    return fName;
}

public Human(String fName, String lName) {
    super();
    this.fName = fName;
    this.lName = lName;
}

public void setfName(String fName) {
    this.fName = fName;
}

public String getlName() {
    return lName;
}

public void setlName(String lName) {
    this.lName = lName;
}

}

public class Student extends Human {

private String grade = null;

public Student(String fName, String lName, String grade) {
    super(fName, lName);
    this.grade = grade;
}

public String getGrade() {
    return grade;
}

public void setGrade(String grade) {
    this.grade = grade;
}

}

public class Worker extends Human {

private int weekSalary = 0;
private int workHoursPerDay = 0;

public Worker(String fName, String lName, int weekSalary, int workHoursPerDay) {
    super(fName, lName);
    this.weekSalary = weekSalary;
    this.workHoursPerDay = workHoursPerDay;
}

public int getWorkSalary() {
    return weekSalary;
}

public void setWorkSalary(int workSalary) {
    this.weekSalary = workSalary;
}

public int getWorkHoursPerDay() {
    return workHoursPerDay;
}

public void setWorkHoursPerDay(int workHoursPerDay) {
    this.workHoursPerDay = workHoursPerDay;
}

public int moneyPerHour() {
    return weekSalary / (5 * workHoursPerDay);
}

}

public class Program {

public static void main(String[] args) {

    ArrayList<Student> student = new ArrayList<>();
    ArrayList<Worker> worker = new ArrayList<>();
}

}

Answer 1

好的，只需添加学生：

ArrayList<Student> students = new ArrayList<>(); // note: students
students.add(new Student("Jens", "Nenov", "A+"));

你可以为工人做几乎完全相同的事情。如果要使用循环，请执行以下操作：

for (int i=0; i<50; i++) {
    students.add(new Student("Jens"+i, "Nenov", "A+"));
}

这将创建一个新学生列表，他们的名字后面有不同的数字。但是，如果您想要不同的数据，则该数据需要来自某个地方。例如，您可能会从用户输入中获取数据：

Scanner input = new Scanner(System.in);
for ...
    System.out.println("Enter a first name:");
    String firstname = input.nextLine();
    ...
    students.add(new Student(firstname, lastname, grade));

用对象动态填充 ArrayList

Dynamically fill in an ArrayList with objects

java

oop

arraylist