使用x和y坐标计算区域，如何在x和y中打破数字组？

Question

This is what I should get.
Sample Output:

Please enter the coordinates in a clockwise order.
    Enter the GPS coordinates for the 1st city: 35.2270869 -80.8431267
    Enter the GPS coordinates for the 2nd city: 32.0835407 -81.0998342
    Enter the GPS coordinates for the 3rd city: 28.5383355 -81.3792365
    Enter the GPS coordinates for the 4th city: 33.7489954 -84.3879824
    The area is: 117863.342

import java.util.Scanner;

public class problem {
    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        System.out.println("Please enter the coordinates in a clowise order");
        System.out.println("Enter the GPS coordinates for the 1st city: ");
        double coordinateOne= input.nextInt();

        System.out.println("Enter the GPS coordinates for the 1st city: ");
        double coordinateTwo= input.nextInt();

        System.out.println("Enter the GPS coordinates for the 1st city: ");
        double coordinateThree= input.nextInt();

        System.out.println("Enter the GPS coordinates for the 1st city: ");
        double coordinateFour= input.nextInt();

        double earthRadius= 6371.01;

        //Get distance


        //distance=(radius)arccos(sin(x1)sin(x2)+cos(x1)cos(x2)cos( y1−y2))
        double distance= (earthRadius)*Math.acos(Math.sin(coordinateOne)*Math.sin(coordinateTwo))
                + Math.cos(coordinateOne)*Math.cos(coordinateTwo);

//      System.out.println("The area is: "+distance);



    }
}

I am having trouble with for example if I enter 35.2270869 -80.8431267 , how do I separate them to x and y ?

I must use the phrase:

Enter the GPS coordinates for the # city.

I need to separate it in order to pass them ( x and y ) to the formula.

Answer 1

Because the values you are after are double , input.nextInt() isn't going to work, instead you should be using nextDouble .

Now, because there are two values, you will need to read it twice...

double coordinateX = input.nextDouble();
double coordinateY = input.nextDouble();

Which, if the input was 35.2270869 -80.8431267 , would assign 35.2270869 to coordinateX and -80.8431267 to coordinateY

You could store the values in an array for easy access...

double city1[] = new double[2];
city[0] = input.nextDouble();
city[1] = input.nextDouble();

You could even use a 2 dimensional array for storing each city...

double coordinates[][] = new double[4][2];
// City #1
coordinates[0][0] = input.nextDouble();
coordinates[0][1] = input.nextDouble();

// City #2
coordinates[1][0] = input.nextDouble();
coordinates[1][1] = input.nextDouble();
//...etc...

Oh, I should point out, you will need to add in a input.nextLine() after you've read the two values to remove the carriage return/newline that is in the stream from when the user pressed Enter

Answer 2

If you are getting 35.2270869 -80.8431267 from the command line as single line, you can not get 35.2270869 -80.8431267 as integer value. Read that value as String like input.readLine(). Then split that String using split() method in String object( use '-' as the delimiter). This method is return a String array. First element of that array is having the value of 35.2270869 and then second element of that array having the 80.8431267. Then you can get those values from the String array and convert those values as double values with Double.parseDouble().

Good Luck !!!. Try and let me know