為什么我的for循環同時添加一個對象？

Question

我有這個應用程序，其數組元素為4.我需要在用戶輸入時將每個Room對象添加到數組中，並且他/她最多可以輸入4個對象。 但是當我只輸入一個Room對象時，它會顯示對象添加的數組中的所有元素。 我可以知道為什么，有人可以幫忙嗎？ 謝謝！

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，我剛剛改變了我的編碼，感謝你們的貢獻，我明白出了什么問題。 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

如果我對你提出正確的問題，你就是說當用戶只輸入一個房間時你的陣列就會變滿。 如果是這種情況我認為。

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

是你的問題，因為它循環遍歷所有數組。

Answer 2

就在這里，您將用一個房間填滿整個陣列。 roomsInHouse.length將始終返回4

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

您可以相應地更改您的代碼

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

然后：

roomsInHouse[n++] = nameOfRoom + dimsOfRoom;

之后只需檢查n < 4 ，這意味着可以添加更多房間。

Answer 3

在do-while循環中你的for循環錯誤......

因為你正在為do-while循環的每次交互迭代“roomsInHouse.lenght”時間......數組被重寫為每次交互....

對您的代碼進行以下更正....

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);
}

}

}