java - 如何按名称删除 arraylist Room 中的房间？

Question

我正在学习java。我在我的 java 程序中遇到了有关 arraylist 的问题。如何删除 Room 中 arraylist 中的房间并计算大小小于 40 的房间数量。我刚刚在 MyRoom 类中编写了 2 个方法:removeRoom 和 countRoomBySize。我的代码在 Net Beans 中出现错误。请任何人帮我检查一下这段代码。非常感谢。这是我的代码 我的主课

public class MyMain { 
public static void main(String[] args) {
    //create a list of rooms
    MyRoom m = new MyRoom();

    m.addRoom(new Room("HB201L",35));
    m.addRoom(new Room("HB401R",45));
    m.addRoom(new Room("211",30));

    m.sort();
    m.list();

    //1.
    m.removeRoom("211");
    m.list();


    //2.
    int c = m.countRoomBySize(40);
    System.out.println(c);//2
}   
}

教室

public class Room implements Comparable<Room> {
@Override
public int compareTo(Room o) {
    return o.name.compareToIgnoreCase(this.name);
}
//instanced variables
private int size;  
private String name;

public Room() {
    name = "";
    size = 0;
}

public Room(String name, int size) {
    this.name = name;
    this.size = size;
}

public int getSize() {
    return size;
}

public void setSize(int size) {
    this.size = size;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}   
}

MyRoom 类

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class MyRoom implements IRoom {

List<Room> rooms;

public MyRoom() {
    rooms = new ArrayList();
}

@Override
public void addRoom(Room r) {
    //append r to the end of list rooms
    rooms.add(r);
}

@Override
public void list() {
    for (int i = 0; i < rooms.size(); i++) {
        Room r = rooms.get(i);
        System.out.printf("%-20s%-10d\n",r.getName(),r.getSize());
    }
}

@Override
public void removeRoom(){
    for (int i = 0; i < rooms.size(); i++) {
        if(rooms.get(i).getName() == "211")
            rooms.remove(rooms);
    }
}

@Override
public int countRoomBySize(){
     int s,i,n;
 n = rooms.size();
 s = 0;
 for(i=0;i<n;i++) {
   if(rooms.get(i).getSize() > 40) 
       s++;  
 }
 return(s); 
}

public void sort() {
    Collections.sort(rooms);
}   
}

Interface IRoom
public interface IRoom {
//only contain public members: constants and method declaration
public final int MAX = 10;
public void addRoom(Room r);
public void list();
public void removeRoom();
public int countRoomBySize();
}
interface A {
void f();
} 
interface B extends A {
void g();
}
interface C {}

Answer 1

首先像这样更改你的界面 IRoom :

public void removeRoom(String name);
public int countRoomBySize(int size);

在 MyRoom 类中更改 removeRoom 方法，如下所示:

@Override
public void removeRoom(String name){
    for (int i = 0; i < rooms.size(); i++) {
        if(name.equalsIgnoreCase(rooms.get(i).getName())){
            rooms.removeIf(r -> r.getName().equals(name));
            System.out.println("Removed !");
        }
    }
}

countRoomBySize 方法如下:

@Override
public int countRoomBySize( int size){
     int s,i,n;
 n = rooms.size();
 s = 0;
 for(i=0;i<n;i++) {
   if(rooms.get(i).getSize() > size) 
       s++;  
 }
 return(s); 
}

祝你好运!