为什么我的for循环同时添加一个对象？

Question

我有这个应用程序，其数组元素为4.我需要在用户输入时将每个Room对象添加到数组中，并且他/她最多可以输入4个对象。 但是当我只输入一个Room对象时，它会显示对象添加的数组中的所有元素。 我可以知道为什么，有人可以帮忙吗？ 谢谢！

import java.util.Arrays;
import java.util.Scanner;
import javax.swing.JOptionPane;

class TestRoom {

public static void main(String [] args)
{
    String[] roomsInHouse = new String[4];
    int answer;

    do{
    String nameOfRoom = JOptionPane.showInputDialog(null, "Enter the name of the room");
    String dimsOfRoom = JOptionPane.showInputDialog(null, "Enter the dimension of the room in feet L X W X H");

    Scanner userInput = new Scanner(dimsOfRoom);
    double l = userInput.nextDouble();
    double w = userInput.nextDouble();
    double h = userInput.nextDouble();

    Room roomDetails = new Room(nameOfRoom, l, w, h);

    String n = Double.toString(l);
    String o = Double.toString(w);
    String p = Double.toString(h);

    for(int i = 0; i < roomsInHouse.length; i++)
    {
        roomsInHouse[i] = nameOfRoom + dimsOfRoom;
    }   

    answer = JOptionPane.showConfirmDialog(null, "Input another room?", "Area/Volume calculator", JOptionPane.YES_NO_CANCEL_OPTION);

    } while(answer == JOptionPane.YES_OPTION);

    for(String j: roomsInHouse)
    {
        System.out.println(j);
    }
}

}

好的，我刚刚改变了我的编码，感谢你们的贡献，我明白出了什么问题。 干杯!

int counter = 0;

roomsInHouse[counter++] = nameOfRoom + dimsOfRoom;  

answer = JOptionPane.showConfirmDialog(null, "Input another room?", "Area/Volume calculator", JOptionPane.YES_NO_CANCEL_OPTION);

} while(answer == JOptionPane.YES_OPTION && counter < 4);

Answer 1

如果我对你提出正确的问题，你就是说当用户只输入一个房间时你的阵列就会变满。 如果是这种情况我认为。

 for(int i = 0; i < roomsInHouse.length; i++)
    {
    roomsInHouse[i] = nameOfRoom + dimsOfRoom;
    }  

是你的问题，因为它循环遍历所有数组。

Answer 2

就在这里，您将用一个房间填满整个阵列。 roomsInHouse.length将始终返回4

for(int i = 0; i < roomsInHouse.length; i++)
{
    roomsInHouse[i] = nameOfRoom + dimsOfRoom;
}

您可以相应地更改您的代码

String[] roomsInHouse = new String[4];
int n = 0;
int answer;

然后：

roomsInHouse[n++] = nameOfRoom + dimsOfRoom;

之后只需检查n < 4 ，这意味着可以添加更多房间。

Answer 3

在do-while循环中你的for循环错误......

因为你正在为do-while循环的每次交互迭代“roomsInHouse.lenght”时间......数组被重写为每次交互....

对您的代码进行以下更正....

import java.util.Arrays;
import java.util.Scanner;
import javax.swing.JOptionPane;

class TestRoom {

public static void main(String [] args)
{
String[] roomsInHouse = new String[4];
int answer;
int counter=0;
do{
String nameOfRoom = JOptionPane.showInputDialog(null, "Enter the name of the room");
String dimsOfRoom = JOptionPane.showInputDialog(null, "Enter the dimension of the room in feet L X W X H");

Scanner userInput = new Scanner(dimsOfRoom);
double l = userInput.nextDouble();
double w = userInput.nextDouble();
double h = userInput.nextDouble();

Room roomDetails = new Room(nameOfRoom, l, w, h);

String n = Double.toString(l);
String o = Double.toString(w);
String p = Double.toString(h);


roomsInHouse[counter] = nameOfRoom + dimsOfRoom;

counter++;
answer = JOptionPane.showConfirmDialog(null, "Input another room?", "Area/Volume calculator", JOptionPane.YES_NO_CANCEL_OPTION);

} while(answer == JOptionPane.YES_OPTION);

for(String j: roomsInHouse)
{
    System.out.println(j);
}

}

}