Read number from file and add them up using Scanner - Java File Path IO

Java examples for File Path IO:Scanner

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Description

Read number from file and add them up using Scanner

Demo Code

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

/**//www  .  java 2s.c  om
 * This version of the program confirms that the
 * Numbers.txt file exists before opening it.
 */

public class FileSum2 {
  public static void main(String[] args) throws IOException {
    double sum = 0.0; // Accumulator, initialized to 0

    // Make sure the file exists.
    File file = new File("Numbers.txt");
    if (!file.exists()) {
      System.out.println("The file Numbers.txt is not found.");
      System.exit(0);
    }

    // Open the file for reading.
    Scanner inputFile = new Scanner(file);

    // Read all of the values from the file
    // and calculate their total.
    while (inputFile.hasNext()) {
      // Read a value from the file.
      double number = inputFile.nextDouble();

      System.out.println("Current number " + number);

      // Add the number to sum.
      sum = sum + number;
    }

    // Close the file.
    inputFile.close();

    // Display the sum of the numbers.
    System.out.println("The sum of the numbers in " + "Numbers.txt is " + sum);
  }
}

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