Re: Need assistance with arrays

From:
Patricia Shanahan <pats@acm.org>
Newsgroups:
comp.lang.java.programmer
Date:
Sat, 17 Nov 2007 08:23:29 -0800
Message-ID:
<fhn4i2$2390$1@ihnp4.ucsd.edu>
RookThis wrote:

I'm new to Java and trying to understand the array process. I have
file that I am trying to read in and populate an array with the
data. I have this so far, but still having problems. Can someone
tell me what I'm doing wrong? Thank you!

public class test
 {
     public static void main (String [] args)throws Exception
     {
         Scanner ifile1 = new Scanner(new File("input.txt"));
         String type = " ";
         String color = " ";
         String description = " ";
         String make = " ";
         int ccount = 0;
         int index = 0;
         carFile[] items = new carFile[50];


This creates an array of 50 null carFile references.

         while (ifile1.hasNext())
             {
                 type = ifile1.next();
                 color = ifile1.nextInt();
                 description = ifile1.next();
                 make = ifile1.nextLine();
                 items[index].setType(type);


You need to make items[index] point to an object, instead of being null,
before you can operate on the object it points to. Perhaps:

items[index] = new carFile();

before this line.

                 items[index].setColor(color);
                 items[index].setDescription(description);
                 items[index].setMake(make);
                 index++;
             }
         ifile1.close();

      }
}

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