Question

我创建了一个Java类，我正在尝试了解ArrayList的工作原理。

假设我有一个名为Complex的顶级课程。在该课程中，我们有Houses，Employees等，其中所有这些都是单独的类。

如果我想创建一个ArrayList我该怎么做呢？

元素的数量是动态的，所以当有人说添加新房子时，我会调用那个询问有关房子的问题的方法，然后将这些全部添加到我假设的列表中？

Answer 1

要创建一个ArrayList来保存House类型的对象，您可以执行以下操作：

ArrayList<House> houseList = new ArrayList<House>();

houseList.add(new House());

循环遍历列表中的所有项目

for(House house:houseList){
   // do something with the house object
}

请参阅the documentation了解其他功能。

Answer 2

试试这个。我将主要写给你;）

import java.util.ArrayList;


public class Complex {
    private ArrayList<House> houses;
    private ArrayList<Employee> employees;

    public void addEmployee(String firstName, String secondName, boolean lazy){
        if(employees == null)
            employees = new ArrayList<Complex.Employee>();

        employees.add(new Employee(firstName, secondName, lazy));
    }

    public void addHouse(String color, boolean withRoof){
        if(houses == null)
            houses = new ArrayList<Complex.House>();

        houses.add(new House(color, withRoof));
    }

    class House{
        private String color;
        private boolean withRoof;
        public String getColor() {
            return color;
        }
        public void setColor(String color) {
            this.color = color;
        }
        public boolean isWithRoof() {
            return withRoof;
        }
        public void setWithRoof(boolean withRoof) {
            this.withRoof = withRoof;
        }
        public House(String color, boolean withRoof) {
            super();
            this.color = color;
            this.withRoof = withRoof;
        }


    }

    class Employee{
        private String firstName;
        private String secondName;
        boolean lazy;
        public String getFirstName() {
            return firstName;
        }
        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }
        public String getSecondName() {
            return secondName;
        }
        public void setSecondName(String secondName) {
            this.secondName = secondName;
        }
        public boolean isLazy() {
            return lazy;
        }
        public void setLazy(boolean lazy) {
            this.lazy = lazy;
        }
        public Employee(String firstName, String secondName, boolean lazy) {
            super();
            this.firstName = firstName;
            this.secondName = secondName;
            this.lazy = lazy;
        }


    }
}

Java类和ArrayList澄清

2 个答案: