java - 如何实现 ArrayList 将 "Room"对象添加到 "House"对象列表中？

Question

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已关闭 10 年前。

我目前正在做作业，我有两个类(class)“房间”和“房子”。作为作业的一部分，我需要启用房屋类将房间存储在 ArrayList 中。 :

Implement a method to read in room information in the House class from the keyboard — this should call the Room constructor as required. Create a zero-argument House constructor to call this new method.

如果这含糊不清或已在其他地方得到回答，我深表歉意，但在尝试理解其他类似查询的解释后，我不知道如何将它们应用到我的情况。

如何申请ArrayList的Room去家庭类吗？

<强> House :

import java.util.ArrayList;
import java.util.Scanner;

public class House {

private int idNum;
private static int internalCount = 0; 
private ArrayList rooms = new ArrayList();
private String address;
private int numRooms;
private String houseType; 

public House (String address, int numRooms, String houseType) {
idNum = internalCount++;

this.address = address;
this.numRooms = numRooms;
this.houseType = houseType;     
}


public House () {
int i = 0;  
idNum = ++internalCount;

Scanner scan = new Scanner(System.in);
scan.useDelimiter("\n");

System.out.println("Enter address of house:");   
address = scan.next();

System.out.println("Enter number of rooms:");   //Number of rooms in the House
numRooms = scan.nextInt();

 while (i < numRooms)  //This will loop until all rooms have been described
 {
 add.room = new Room[100]; //I understand this is incorrect but I don't know what  I should have in here
 i++;
 }

 System.out.println("Enter type of house:");
 houseType = scan.next();
 }
 public void addroom(String description, double length, double width)
 {

 }

 int getIdNum() {
 return idNum;
 }


 @Override

 public String toString()
 {
  String report = "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n";
  report += "Address: " + address + "\n";
  report += "No. of Rooms: " + numRooms + "\n";
  report += "House Type: " + houseType+ "\n";
  report += "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n";

  return report;
 }
 }

<强> Room :

import java.util.Scanner;

public class Room {

private String description;
private double length;
private double width;

public Room (String description, double length, double width) {
this.description = description;
this.length = length;
this.width = width;     
}

public Room () {
Scanner scan = new Scanner(System.in);
scan.useDelimiter("\n");

System.out.println("Enter description of room:");
description = scan.next();

System.out.println("Enter length of room:");
length = scan.nextDouble();

 System.out.println("Enter width of room:");
 width = scan.nextDouble();
 }

 /*
 * Calculates and returns area of Room
 */
 public double getArea () {
 return length*width;
 }


 @Override
 public String toString() {
 return description + "- Length: " + length + "m; Width: " + width + 'm';
 }   
}

Answer 1

您检查过API吗？对于数组列表？

你需要这样的东西:

rooms.add(new Room());

此外，我将利用 Java 泛型并这样定义列表:

private ArrayList<Room> rooms;

这利用了 generics ，并确保这只能是房间列表，而不是杂项对象。这将为您省去一些麻烦，因为您不会无意中将房屋添加到房间列表中(通过编程错误)