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Thread: whats wrong with my program??

  1. #1
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    Default whats wrong with my program??

    I am writing a program that reads data from a file, converts it to integers and than displays 30% of the value...but i cannot get it to work...can someone give me a tip on this please.....

    public class K {	
    	public static void main (String[] args) throws IOException
    	{
    		int value;
    		String fileName;
    		String income;
    		double finalList=0;
    		fileName=JOptionPane.showInputDialog("Enter the file name: ");
    		try
    		{
    			double tax = 0;
    			FileReader freader=new FileReader(fileName);
    			BufferedReader  inputFile= new BufferedReader(freader);
    			income= inputFile.readLine();
    			value=Integer.parseInt(income);
    			while(income!=null)
    			{
    				tax=(value)*.30;
    				finalList+=tax+'\n';
    				income=inputFile.readLine();
    				tax=Double.parseDouble(income);
     
    			}
    			JOptionPane.showMessageDialog(null, tax+'\n');
    			inputFile.close();
    		}
    		catch (FileNotFoundException e)
    		{
    			JOptionPane.showMessageDialog(null, "file not found");
     
    		}
    	}
    }
    Last edited by helloworld922; May 9th, 2010 at 11:15 AM. Reason: please use [code] tags


  2. #2
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    Default Re: whats wrong with my program??

    I am writing a program that reads data from a file, converts it to integers and than displays 30% of the value...but i cannot get it to work...can someone give me a tip on this please.....
    What happens when you run it?

  3. The Following 2 Users Say Thank You to smarty187 For This Useful Post:

    JavaPF (May 10th, 2010), Json (May 10th, 2010)

  4. #3
    Super Moderator Json's Avatar
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    Default Re: whats wrong with my program??

    I think the logic in your program is somewhat flaw.

    You only read the value from the first line of the file you open and after that you loop through each line in the file reading in each line and storing it in the tax variable which then gets overwritten in the next while cycle by value x 0.30, no matter what the tax you add to the finalList will always be the same. On another note finalList is a primitive double and you try to increase it and add \n to the end?

    finalList+=tax+'\n';

    Should that not just read.

    finalList += tax;

    // Json

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    jrodriguo (May 11th, 2010)

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    Default Re: whats wrong with my program??

    Quote Originally Posted by jrodriguo View Post
    can someone give me a tip on this please.....

    your while loop was wrong when the file contained multiple lines. to read multiple line use my while loop.

    import java.io.BufferedReader;
    import java.io.FileNotFoundException;
    import java.io.FileReader;
    import java.io.IOException;
     
    import javax.swing.JOptionPane;
     
     
    public class TestClass {
     
    		public static void main (String[] args) throws IOException
    		{
    			int value;
    			String fileName;
    			String income;
    			double finalList=0;
    			String allIncome = "";
    			fileName=JOptionPane.showInputDialog("Enter the file name: ");
    			try
    			{
    				double tax = 0;
    				FileReader freader=new FileReader(fileName);
    				BufferedReader  inputFile= new BufferedReader(freader);
    				while((income= inputFile.readLine())!=null)
    				{
    					value = Integer.parseInt(income);
    					tax=value / 3.0;
    					finalList+=tax;
    					allIncome+=tax + "\n";
    				}
    				JOptionPane.showMessageDialog(null, allIncome);
    				inputFile.close();
    			}
    			catch (FileNotFoundException e)
    			{
    				JOptionPane.showMessageDialog(null, "file not found");
     
    			}
    		}
    	}

    have fun.

  7. The Following User Says Thank You to j2me64 For This Useful Post:

    jrodriguo (May 11th, 2010)

  8. #5
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    Default Re: whats wrong with my program??

    thanks everyone...this worked out for me great...really appreciate everyone's help

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