Question

我正在尝试按字段对对象数组进行排序，但我不断收到此错误，说明＆＃34;价格/位置无法解析或不是字段＆＃34;，即使它们都是字段，也已声明在Realestate类中。关于＆＃34;我不是一个领域＆＃34;我得到了同样的错误。当我处理ArrayList时，所以我转移到简单的对象数组，我仍然得到相同的错误。我究竟做错了什么？我找到了有关将数组与Comparable和Comparator进行比较的信息，但我不知道如何将任何结果应用于排序例程。请帮忙！这些是我的文件：

档案房地产：

public class Realestate {
    static String location = "";
    static String description = "";
    static String price = "";

    // constructor
    public Realestate(String loc, String desc, String prc) {
        location = loc;
        description = desc;
        price = prc;
    }
}

文件RealestateFinder：

import java.util.*;

public class RealestateFinder {

    // Hold properties' info
    static String[] locations = {"Miami", "Las Vegas", "Paris", "London"};
    static String[] descriptions = {"1-bedroom", "2-bedrooms", "3-bedrooms", "penthouse"};
    static String[] prices = {"1,000,000", "2,000,000", "3,000,000", "4,000,000"};

    // Sort per field
    public static void sortArray(Realestate arr[]) {
        for(int x = 0; x < arr.length; ++x) {            
            //use array Sort
            Arrays.sort(arr);
        }           
    }

    public static void main(String[] args) {        
        int numProperties = 4;

        //Create new Realestate object newProperty
        Realestate[] newProperty = new Realestate[numProperties]; 

        // Initialize array of objects Realestate[] newProperty using arrays from top
        for(int x = 0; x < newProperty.length; ++x) {
            newProperty[x] = new Realestate(locations[x], descriptions[x], prices[x]); // constructor
        }

        //Get user's input
        //...

        while(true) {
            if(holdUserInput == 1) {
                //sort per price
                sortArray(newProperty.price);//price cannot be resolved or is not a field
                break;
            }

            else if(holdUserInput == 2) {
                // sort per location
                sortArray(newProperty.location);//location cannot be resolved or is not a field
                break;
            }

            else {
                System.out.println("Program Ended \n");
                break;
            }// end else statement
        }// end while loop
    }// end main()
}// end class RealestateFinder

Answer 1

首先，您可能不会对3个字段使用静态，static表示它与特定实例无关，而不是您想要的

然后使用List更容易排序：

int numProperties = 4;
List<Realestate> list = new ArrayList<>();
for (int x = 0; x < numProperties; ++x) {
    list.add(new Realestate(locations[x], descriptions[x], prices[x]));
}

然后，使用现有的排序方法更快更容易使用：

while (true) {
    if (holdUserInput == 1) {
        list.sort(Comparator.comparing(Realestate::getPrice));
        break;
    } else if (holdUserInput == 2) {
        list.sort(Comparator.comparing(Realestate::getLocation));
        break;
    } else if (holdUserInput == 2) {
        list.sort(Comparator.comparing(Realestate::getDescription));
        break;
    } else {
        System.out.println("Program Ended \n");
        break;
    }// end else statement
}

最后，因为没有理由使用while(true)和break，所以最好更好地使用switch：

switch (holdUserInput) {
    case 1:
        list.sort(Comparator.comparing(Realestate::getPrice));
        break;
    case 2:
        list.sort(Comparator.comparing(Realestate::getLocation));
        break;
    case 3:
        list.sort(Comparator.comparing(Realestate::getDescription));
        break;
    default:
        System.out.println("Program Ended \n");
        break;
}

在Java中按字段排序对象数组：＆＃34;变量无法解析或不是字段＆＃34;

1 个答案: