Question

In Java, write a program that asks the user for the name of a file. The program should read all the numbers from the given file and display the total and average of all numbers in the following format (three decimal digits):

Total: nnnnn.nnn

Average: nnnnn.nnn

Class name: FileTotalAndAverage

Answer 1

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

public class FileTotalAndAverage {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter file name: ");
        File file = new File(in.nextLine());
        try {
            Scanner fin = new Scanner(file);
            double total = 0, count = 0;
            while (fin.hasNextDouble()) {
                total += fin.nextDouble();
                ++count;
            }
            System.out.printf("Total: %.3f\n", total);
            System.out.printf("Average: %.3f\n", total/count);
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " is not found!");
        }
        in.close();
    }
}