Thread: Copying a file to an array and getting exception thrown for input

I am trying to copy the contents of a file into an array.
The contents of the file is
John X Doe 4.0 6 8.2 9

The code the instructor wrote on the board. I inputted it and when trying to run I get the error
Exception in thread "main" java.lang.NumberFormatException: For input string: "Doe"
at sun.misc.FloatingDecimal.readJavaFormatString(Floa tingDecimal.java:1224)
at java.lang.Double.parseDouble(Double.java:510)
at fileToArray.getInput(fileToArray.java:37)
at fileToArray.main(fileToArray.java:16)

I am not sure what happened. Can anyone assist? Thanks

import java.util.Scanner;
import java.io.*;
import java.util.StringTokenizer;
 
public class fileToArray
{
  public static void main(String[] args) throws IOException
  {
    String[] names = new String[39]; // array to hold names from a file
    double[][] reals = new double[39][2]; 
    int[][] ints = new int[39][2];
 
    Scanner inFile = new Scanner(new File("Summer13.txt")); // file to get input
    PrintWriter outFile = new PrintWriter("Summer13.out");  // file to write output
 
    int n = getInput(names, reals, ints, inFile);
    int left = leftOver(inFile);
 
  }
   //Methods
     public static int getInput(String[] names, double[][] reals, int[][] ints, Scanner inFile)
     {
      int i = 0,  m;
      String line;
      StringTokenizer st;
 
      //while loop to read file
      while(i < names.length && inFile.hasNext())
      {
         line = inFile.nextLine();
         st = new StringTokenizer(line);
         m = st.countTokens();
         for(int j = 1; j < m-4; j++)
         {
            names[i] = names[i] + " " + st.nextToken();
         }
         reals[i][0] = Double.parseDouble(st.nextToken());
         ints[i][0] = Integer.parseInt(st.nextToken());
         reals[i][1] = Double.parseDouble(st.nextToken());
         ints[i][1] = Integer.parseInt(st.nextToken());
         i ++;
      }
 
          return i;
     }
 
 
 
 
      public static int leftOver(Scanner inFile)
      {
        int left = 0;
        while(inFile.hasNext())
        {
          left++;
          inFile.nextLine();
        }
         return left;
      }
 
}

Out of respect of Java naming conventions, class names should begin with capital letters.

Are you required to use StringTokenizer, or can you use String.split()? If you can use split(), I recommend it.

Instructor gave us an assignment to do which was the final for her CS1 class. I did not have this instructor and did not learn StringTokenizer or String.split() in my CS1 class. StringTokenizer was what she wrote when putting this up on the board. I did not notice the typo in my class header. Thanks.

I am trying to copy the contents of a file into an array.
The contents of the file is
John X Doe 4.0 6 8.2 9

I had some typos and it would not read the names. Now I got the names storing to an array and when I
print out the index it shows the John X Doe

When I am trying to store a number it works with no error but when I try and output the index[0] its not a number but this is shown
[I@1f934ad

I am not sure what happened. Can anyone assist? Thanks

import java.util.Scanner;
import java.io.*;
import java.util.StringTokenizer;
 
public class FileToArray
{
  public static void main(String[] args) throws IOException
  {
    String[] names = new String[39]; // array to hold names from a file
    double[][] reals = new double[39][2]; 
    int[][] ints = new int[39][2];
 
    Scanner inFile = new Scanner(new File("Summer13.txt")); // file to get input
    PrintWriter outFile = new PrintWriter("Summer13.out");  // file to write output
 
    int n = getInput(names, reals, ints, inFile);
    int left = leftOver(inFile);
 
  }
   //Methods
     public static int getInput(String[] names, double[][] reals, int[][] ints, Scanner inFile)
     {
      int i = 0,  m;
      String line;
      StringTokenizer st;
 
      //while loop to read file
      while(i < names.length && inFile.hasNext())
      {
         line = inFile.nextLine();
         st = new StringTokenizer(line);
         m = st.countTokens();
         names[i] = st.nextToken();
 
         for(int j = 1; j < m-4; j++)
         {
            names[i] = names[i] + " " + st.nextToken();
         }
         reals[i][0] = Double.parseDouble(st.nextToken());
         ints[i][0] = Integer.parseInt(st.nextToken());
         reals[i][1] = Double.parseDouble(st.nextToken());
         ints[i][1] = Integer.parseInt(st.nextToken());
         i ++;
      }
 
          return i;
     }
 
 
 
 
      public static int leftOver(Scanner inFile)
      {
        int left = 0;
        while(inFile.hasNext())
        {
          left++;
          inFile.nextLine();
        }
         return left;
      }
 
}

Hello.
Can you please provide your print statements?
If you want to print an array using System.out.println(array) then it will not print the elements of array. Instead it will print the hashcode of an object. Because arrays are treated as objects in java.
So you will need to traverse the entire array and print individual elements by yourself.

Syed.

Sorry that was just meant to imply that I was printing index 0 of the array's. When I went back to check the code I seen that I was trying to print a [] array when they were [][]. I made the change and now it is working. Thanks a lot.

Originally Posted by KristopherP

I am trying to copy the contents of a file into an array.

I'm confused over the instructions. An array, as in singular?

Originally Posted by KristopherP

The contents of the file is
John X Doe 4.0 6 8.2 9

One single line? Or are there more lines? Will each line contain the same exact setup, which appears to be:
firstName middleInitial lastName double int double int

Originally Posted by KristopherP

The code the instructor wrote on the board.

The instructor give you the code you are supposed to write? Again I do not understand what you mean here.

Originally Posted by KristopherP

Exception in thread "main" java.lang.NumberFormatException: For input string: "Doe"
at sun.misc.FloatingDecimal.readJavaFormatString(Floa tingDecimal.java:1224)
at java.lang.Double.parseDouble(Double.java:510)
at fileToArray.getInput(fileToArray.java:37)
at fileToArray.main(fileToArray.java:16)

I am not sure what happened. Can anyone assist? Thanks

The exception means that "Doe" is not a number.
Add some printlns to see the value of the variables like line, st, m... this will show the symptoms in more detail and help discover the cause

--- Update ---

Please do not double post your questions
Threads merged