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Thread: Parsing input from a file using Scanner

  1. #1
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    Default Parsing input from a file using Scanner

    I'm sorry if the thread title is misleading I solved my initial problem but ran into another one. I'm having some kind of weird problem reading input from a file. It says that my scanner object I'm using to hold an item of information isn't initialized, when I do try to initialize it, it says error variable already initialized. I'm using the scanner to read input from a file whose contents are this

    10
    150.4
    88.4
    -3.14
    499.4
    799.4
    1299.8
    0
    1900.2
    901.7
    4444.4

    This is my program

    import java.util.*;
    import java.io.*;
     
    public class QudratullahMommandi_3_07
    {
     
      Toolkit_General toolKit = new Toolkit_General();
     
      public static void main (String[]args)throws IOException
      {
     
     
      double rentalCost = 0;
      double mileage;
      int controlVar;
      String inputFile = "QudratullahMommandi_3_07_Output.txt";
     
     
       SummaryStatement();
       File file = new File(inputFile);
       Scanner inputRead = new Scanner(file);
     
     
     
       TableHeading();
     
       controlVar = inputRead.nextInt();
     
     
       for (int index = 0; index < controlVar; index++);
        { 
     
          String holder = inputRead.nextLine();
          String holder2 = holder2.trim();
          mileage = Double.parseDouble(holder2);
     
          if (mileage <=0)
          { 
           System.out.println("*****");
          }
          else if (mileage < 400)
          { 
           rentalCost = mileage*.18;
          }
          else if (mileage < 900)
          { 
           rentalCost = 65.00 + (.15 * (mileage-400));
          }
          else if (mileage < 1300)
          { 
           rentalCost = 115.00 + (.12 * (mileage-800));
          }
          else if (mileage < 1900)
          {
            rentalCost = 140.00 + (.10 * (mileage-1200));
          }
          else if (mileage < 2600)
          {
            rentalCost = 165.00 + (.08 * (mileage-1800));
          }
          else if (mileage >= 2600)
          { 
           rentalCost = 195.00 + (.06 * (mileage-2500));
          }
     
          System.out.println(rentalCost);
     
         }// end for loop
     
     
     
      }// end main
     
     
     
     
      public static void SummaryStatement()
      { 
          System.out.println("This program reads a list of values representing number of miles"
          + " driven by individuals.\n" + "It will output the dollar amount their rental cars cost.");   
      }// end SummaryStatement
     
     
      public static void TableHeading()
      { 
          System.out.println();
          System.out.println("Number of miles traveled on the left as well as amount reimbursed on the right");
          System.out.println("------------------------------------------------");
          System.out.println("Miles Driven" + "                   " + "Amount reimbursed");
      }
     
     }// end class

    This is the error message


    QudratullahMommandi_3_07.java:34: error: variable holder2 might not have been initialized
    String holder2 = holder2.trim();
    ^
    1 error

    ----jGRASP wedge2: exit code for process is 1.
    ----jGRASP: operation complete.
    Last edited by Helplessdrowningpuppy; March 26th, 2014 at 02:56 AM.


  2. #2
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    Default Re: Parsing input from a file using Scanner

    it is either you make you controlVar a double premitive type. or
    cast what you have parse to int premitive type : controlVar = (int) Double.parseDouble(numberOfValues);

    because your controlVar is integer and your trying to put a value on it which has a premitive type of double.

  3. #3
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    Default Re: Parsing input from a file using Scanner

    Yes, it was inappropriate to delete your original question and change it to a new question. dicdic's answer is completely out of context and makes no sense.

    Next time, mark your first thread solved and start a new thread for your new question.

    As for your current question, you're confused. holder2 is not a Scanner object; it's a String object, and I think you meant this statement:

    String holder2 = holder2.trim();

    to be:

    String holder2 = holder.trim();

    Tired?

  4. The Following User Says Thank You to GregBrannon For This Useful Post:

    Helplessdrowningpuppy (March 26th, 2014)

  5. #4
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    Default Re: Parsing input from a file using Scanner

    I was tired to the point of mild retardation making this thread, dicdic helped me out with something obvious, so ty, I have another question related to this same program but I'll start a new thread for it.

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