Question

Java.

1. (20 pts)          Write a program that reads all the numbers from the file mynums.dat and prints out the sum of the positive values from the file. Assume that the file contains only numeric values. You must output an error if the file can't be opened. You must write the complete program and the output when the program runs successfully must conform exactly to the sample output.

Bonus ( 5 pts). Output an error if the file contains non-numeric values.

/* sample run:

The positives sum to 251.650!

*/

import java.io.File;

import java.io.FileNotFoundException;

import java.util.Scanner;

public class FindSum {

   public static void main(String[] args) {

   }

}

Answer 1

/* sample run:
    The positives sum to 251.650!
*/

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class FindSum {

    public static void main(String[] args) {
        File file = new File("mynums.dat");
        try {
            Scanner fin = new Scanner(file);
            double num, sum = 0;
            while (fin.hasNextDouble()) {
                num = fin.nextDouble();
                if (num > 0) {
                    sum += num;
                }
            }
            System.out.println("The positives sum to " + sum + "!");
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " does not exists!");
        }
    }

}