Counting number of entries in a file

[lenny0]

Hi all,

I am having problems with counting the number of entries (doubles) in a file as specified by user input. The file opens fine and begins to count, however the accumulator never progresses past 1. also when counting a file with no entries, it never returns as zero, but always 1.

Below is the code of the offending method.

import java.io.*;
import java.util.Scanner;

public class Calculate
{
  static String fName; 
  static int count;
  static double num[];
  static double m;
  static double var;

   /**the countData method returns the number of entries of type double in file.
      @return The value in the entries filed.
   */

  public static int countData() throws IOException
  { 
    String fileName = "";      //file name as input by user
    fName = fileName;        //passes fileName reference to class variable fname
    int entries = 0;	       //accumulator for number of file entries
    count = entries;            //passes entries reference to class variable count

    //create instance of scanner class to capture user input
    Scanner keyboard = new Scanner(System.in);
    //prompt user for input
    System.out.print("Enter file name: ");
    //assign reference to local variable
    fileName = keyboard.nextLine();
    //create an instance of file class to reference fileName
    File file = new File (fileName);
    //create instance of scanner class to read from file
    Scanner inputFile = new Scanner(file);
    //increment the accumulator while more entries exist in the file
    while (inputFile.hasNextDouble())
	  inputFile.nextDouble();
          entries++;
    //close the file
    inputFile.close();
    //if less than 2 entries are in file, prompt user that more are required
    if (entries <2)
       System.out.println("The file " +fileName +" needs to contain more than 1 entry");
    //verifying accumulator is working, which it is not!
    System.out.println("number of entries is: " +entries);
    return entries;
  }//end of countData method
}

[Junky]

while (inputFile.hasNextDouble())
	  inputFile.nextDouble();

That is your loop. Indenting the next line does not make it automagically inside the loop.

[sunde887]

edit: Junky is right. Wrap your loop in curly braces if you have more than 1 statement(or always do it so you don't run into errors like this)

[lenny0]

Thanks Juky. I have been staring at this for so long that I was blind to this. Below is the fix.

while (inputFile.hasNextDouble())
{
inputFile.nextDouble();
entries++;
}