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Thread: Please help with my code

  1. #1
    Junior Member
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    Default Please help with my code

    This code is to have a method that takes ints from a txt file and puts them in an array. I created a method that takes the name of the file nad the size of the array need to be created. The data is extracted from the file seems to be working fine when I print it out. But the array when printed only has one number instead of the many different numbers.

    The method code

    public static int[] fillarray(int n , String filename)
    {
     
     int [] arrs;
     arrs = new int[n];
    try
    { FileReader fr = new FileReader(filename);
      BufferedReader inputStream = new BufferedReader(fr);
    String line = null ;
    while((line = inputStream.readLine()) != null)
    { System.out.println(line);
    int temp = Integer.parseInt(line);
     
     for( int i = 0; i < n; i++)
     {
      arrs[i] = temp;
    }
    }
    inputStream.close();
    }
    catch(IOException e)
    {
    System.out.print("Error in Reading the file");
    }
    return arrs;
    }

    Thank You for any help you can provide
    Last edited by dacoach1549; April 28th, 2012 at 01:11 PM.


  2. #2
    Super Moderator pbrockway2's Avatar
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    Default Re: Please help with my code

    the array when printed only has one number
    That's exactly what the for loop is doing: it's putting temp (which was obtained from a line in the file) into every array slot.

    for( int i = 0; i < n; i++)
    {
        arrs[i] = temp;
    }

    A for loop isn't appropriate. Rather you should assign the value of temp to some particular array position, which means worrying about which position.
    Last edited by pbrockway2; April 28th, 2012 at 05:06 PM. Reason: sorry for corrrections: first coffee of am

  3. #3
    Junior Member hackthisred's Avatar
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    Default Re: Please help with my code

    I recommend using a List instead of an array for this operation, assuming you don't already know the number of entries that will be recorded from the file as input.
    import java.io.BufferedReader;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
     
     
    public class Stuff {
     
    	public static List fillarray(String filename)
    	{
     
    		List<Integer>  arrs = new ArrayList<Integer>();
    	try
    	{ 
    		FileReader fr = new FileReader(filename);
    		BufferedReader inputStream = new BufferedReader(fr);
    		String line = null ;
    		while((line = inputStream.readLine()) != null)
    		{ 
    			System.out.println(line);
    			arrs.add(Integer.parseInt(line)) ;
    		}
     
    		inputStream.close();
    	}
    	catch(IOException e)
    	{
     
    		System.out.print("Error in Reading the file");
    	}
    		return arrs;
    	}
     
    }
    p.s. formatting is important, make it a habit now while your learning the language
    Last edited by hackthisred; April 29th, 2012 at 10:29 PM. Reason: remove uneeded parameters as part of the method
    f34r th3 kut3 1z

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