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Thread: Help with Program

  1. #1
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    Default Help with Program

    I wrote this program and while it does everything it should, but I am not sure if it is correct. I need the program to take all the even numbers and write to a .dat file. Then I need to close the file, reopen it, and display the results. After that I need to get the odd numbers and add them to the end of the file. Then reopen the file and display the results. Is this correct?


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

    public class Numbers {
    // The main function
    private static FileOutputStream output;
    private static FileInputStream input;
    private static ArrayList<Integer> inputList;
    static int sumEven = 0;
    static int sumOdd = 0;

    public static void main(String[] args) throws IOException
    {
    createOutputFileEven();
    createInputFile();
    printInputList();
    createOutputFileOdd();
    createInputFile();
    printInputList();
    }
    private static void createOutputFileEven() throws IOException
    {
    //create the output file
    output = new FileOutputStream("numbers.dat");
    //output test values to the file
    for(int i = 2; i <= 100; i +=2)
    {
    sumEven = sumEven + i;
    output.write(i);
    }
    System.out.print("The sum of the Even numbers is " + sumEven + ".\n");
    output.close();
    }//end private static void creatOutputFile
    private static void createOutputFileOdd() throws IOException
    {
    //create the output file
    output = new FileOutputStream("numbers.dat");
    //output test values to the file
    for(int i = 1; i < 100; i += 2)
    {
    sumOdd =sumOdd + i;
    output.write(i);
    }
    //close the output stream
    System.out.print("The sum of the Even numbers is " + sumOdd + ".\n");
    output.close();
    }//end private static void creatOutputFile
    private static void createInputFile() throws IOException
    {
    inputList = new ArrayList<Integer>(10);
    int value;

    input = new FileInputStream("numbers.dat");
    while ((value = input.read()) != -1)
    inputList.add(value);
    }
    private static void printInputList()
    {
    String output;
    if (inputList.size() > 0)
    {
    output = "The values are:\n";
    for(int i = 0; i < inputList.size(); i++)
    if (i == 0)
    output += inputList.get(i);
    else
    output += ", " + inputList.get(i);
    }
    else
    {
    output = "No values in the input list";
    }
    System.out.println(output);
    }
    }


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Help with Program

    Is this correct?
    Have you compiled and executed the program and looked at the results?
    Were the results correct?

  3. #3
    Super Moderator Norm's Avatar
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    Default Re: Help with Program

    Please edit your post, select the code and wrap it in code tags to preserve its formatting.
    See: BB Code List - Java Programming Forums - The Java Community
    Or press the Go Advanced button below the edit box and use the # icon

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