Re: Issue with array length in for loop

From:
Lew <noone@lewscanon.com>
Newsgroups:
comp.lang.java.help
Date:
Sat, 25 Dec 2010 20:28:58 -0500
Message-ID:
<if65od$7vt$1@news.albasani.net>
On 12/25/2010 06:01 PM, Steven Kennedy wrote:

Thanks for all the interest so far. Here is the code (note: I have


DO NOT USE TAB CHARACTERS TO INDENT USENET POSTS, PLEASE.

Use space characters, up to four per indent level.

changed things around a little bit based on peoples suggestions, but
am still having the same error).

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Vector;


Why did you choose 'Vector'? It's been out of date for, what, 12 years?

public class HorseExample {

    public HorseExample(){

You don't need to specify a do-nothing, no-argument constructor, although it's
not harmful to do so.

     }
    //Class for Jockey, stores the jockey's name and price
    public class Jockey {

Why is 'Jockey' a nested class?

         private Float price;

Why are you using 'Float' for a price? 'float' is worse than 'double', which
is not suitable for money representation, let alone the reference versions
thereof. What motivated your choice?

         private String fullName;

        //Initialisation
        public Jockey (String fullName, Float price) {
            this.fullName = fullName;

If you never change these values, you should make them 'final'.

             this.price = price;
        }

        //Getters
        public String getFullName () {
            return fullName;
        }

        public Number getPrice () {
            return price;
        }
    }

    //Class for race, stores an array of jockeys running in the race and
the race number
    public class Race {

Again, why an inner class?

         private Jockey[] jockeys;
        private int number;

        //Initialisation
        public Race(){

        }

        public Race (int number, Jockey[] jockeys) {
            this.number = number;
            this.jockeys = jockeys;
        }

        //Getters
        public int getNumber () {
            return this.number;
        }

        public Jockey[] getJockeys () {
            return this.jockeys;
        }

        public int getRunners () {
            return this.jockeys.length;
        }
    }

    public static void main(String[] args) {
        HorseExample he = new HorseExample();

        //Initialise the variables
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
        Race[] races = {he.new Race()};

The internal array of 'Jockey' in this new 'Race' instance will NEVER receive
new values.

         String raceCode = "R";
        String meetingCode = "S";
        int raceCount = 0;

        //Get the track information
        try {
            Date date = df.parse("2010-12-26");

            //Get the number of races for the meeting
            URL url = new URL("http://www.tab.com.au/Racing/Information/" +
                    "DisplayRaces.aspx?State=2&MeetingCode="
                    + meetingCode + "&RacingCode=" + raceCode
                    + "&FromDate=" + df.format(date) + "T00:00:00");

Stupid TAB indentation. You should make your code readable.

             BufferedReader in = new BufferedReader(new
InputStreamReader(url.openStream()));
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                if (inputLine.contains("javascript:WP")) {

Oy, vey.

                     raceCount = Integer.parseInt(inputLine.split("javascript:WP")
[1].split("'")[5]);
                }
            }

            //Populate the race array
            Vector<Race> raceVect = new Vector<Race>();

That's not an array. Don't use 'Vector'. Use a 'List' like 'ArrayList'.

             for (int i=1;i<=raceCount;i++) {
                Vector<Jockey> jockVect = new Vector<Jockey>();
                String tmpRace = "0" + Integer.toString(i);
                if (tmpRace.length()==3){
                    tmpRace = tmpRace.substring(1);
                }

WTF?

                 url = new URL("http://www.tab.com.au/Racing/Betting/StandardBets/"
+


.... indecipherable crap elided ...

                 Jockey[] jArray = new Jockey[jockVect.size()];
                raceVect.add(he.new
Race(Integer.parseInt(tmpRace),jockVect.toArray(jArray)));
                }

Wow. Use collections or use arrays. Pick a technique, for God's sake.

             }
            races = raceVect.toArray(new Race[raceVect.size()]);

Why did you set 'races' to one array that you never used, only to set it to
another later?

             //Go through the races
            System.out.println("Number of races: " + raceCount);
            for (Race race : races) {
                System.out.println("For race " + race.getNumber()
                        + " there is " + race.getRunners() + " horses");
            }

        //Error handling

Yeah, uh-huh.

         } catch (MalformedURLException e) {
            System.err.println("Malformed URL exception: " + e.getMessage());
        } catch (IOException e) {
            System.err.println("IO exception: " + e.getMessage());
        } catch (ParseException e) {
            System.err.println("Parse exception: " + e.getMessage());
        }

    }

}


I don't have the patience to untangle this mess. The problem is that it is
very, very tangled. For starters, use arrays or use collections, not both.
Simplify your logic. Don't declare variables until you use them. Don't be so
freaking complicated.

--
Lew
Ceci n'est pas une pipe.

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