Question

import java.util.Scanner;

public class Chpt4_Project {

    private static Scanner input;

    public static void main(String[] args) {

        input = new Scanner(System.in);

        System.out.print("Enter the first city: ");
        // Prompt user for city
        String city1 = input.nextLine();

        System.out.print("Enter the second city: ");
        // Prompt user for the second city
        String city2 = input.nextLine();

        System.out.print("Enter the latitude and longitude of the first city separated by a space (Ex. 28.8 81.2): ");
        String coord1 = input.toString();
        // Save coordinates as a string
        String [] tempArray1 = coord1.substring(coord1.indexOf("(")+1, coord1.lastIndexOf(")")).split(" ");
        // Split string
        double lat1 = Double.parseDouble(tempArray1[0]);
        double long1 = Double.parseDouble(tempArray1[1]);


        System.out.print("Enter the latitude and longitude of the second city separated by a space (Ex. 28.8 81.2): ");
        String coord2 = input.toString();
        // Save coordinates as a string
        String [] tempArray2 = coord2.substring(coord2.indexOf("(")+1, coord2.lastIndexOf(")")).split(" ");
        // Split string
        double lat2 = Double.parseDouble(tempArray2[0]);
        double long2 = Double.parseDouble(tempArray2[1]);

        double x = (long1 - long2) * 55;
        double y = (lat1 - lat2) * 69;
        double distance = Math.sqrt(x*x+y*y);

        System.out.println("The distance between " + city1 + city2 + " is " + distance + "miles.");
    }

}

入门编码的学生，我正在尝试编写一个程序，该程序将告诉我两个城市坐标之间的距离。但是，当我尝试将字符串拆分为经度和纬度时，我似乎无法获得{ {1}}对。

这是结果，在此先感谢！

tempArrays

Answer 1

解决了尝试在代码下运行的问题

import java.util.Scanner;


public class Main{
private static Scanner input;
     public static void main(String []args){

         input = new Scanner(System.in);

    System.out.print("Enter the first city: ");
    // Prompt user for city
    String city1 = input.nextLine();
    System.out.print("Enter the second city: ");
    // Prompt user for the second city
    String city2 = input.nextLine();

    System.out.print("Enter the latitude and longitude of the first city separated by a space (Ex. 28.8 81.2): ");
    String coord1 = input.nextLine();
    // Save coordinates as a string
    String [] tempArray1 = coord1.split(" ");
    // Split string
    double lat1 = Double.parseDouble(tempArray1[0]);
    double long1 = Double.parseDouble(tempArray1[1]);


    System.out.print("Enter the latitude and longitude of the second city separated by a space (Ex. 28.8 81.2): ");
    String coord2 = input.nextLine();
    // Save coordinates as a string
    String [] tempArray2 = coord2.split(" ");
    // Split string
    double lat2 = Double.parseDouble(tempArray2[0]);
    double long2 = Double.parseDouble(tempArray2[1]);

    double x = (long1 - long2) * 55;
    double y = (lat1 - lat2) * 69;
    double distance = Math.sqrt(x*x+y*y);

    System.out.println("The distance between " + city1 + city2 + " is " + distance + "miles.");




     }
}

Answer 2

您的问题是，在查询纬度和经度时，您没有阅读新的输入内容。您实际上是在将Scanner对象转换为字符串，然后尝试解析它，这显然不是您的目标。只需按如下所示从用户那里读取新输入即可：

System.out.print("Enter the latitude and longitude of the first city separated by a space (Ex. 28.8 81.2): ");
String coord1 = input.toString(); //Needs to be replaced

第二行应替换为input.nextLine();

第二个要求纬度和经度的代码也是如此。

如何使用tempArray将字符串拆分为两个双精度？

2 个答案: