New to Java and I guess a scope question.

Question

Hello and thank you for taking the time to read this. I am not a real programmer, everything I have ever done was a total hack, or written without a full understanding of how I was doing it. One thing about Java is that you might have like 20 classes (or interfaces or whatever), and that code is "all over" (which means to me not on one big page). My comment statements may look odd to others, but the program is for me alone and well, only I need to understand them.
Through some hacking, I wrote/copied/altered the following code:
import java.io.*;
import java.util.*;
public class readDataTest
     public static void main(String[] args)
          /* get filename from user, will accept and work with drive name
          e.g. c:\java\data.txt, if it is the same drive as the compiler
          does not need the directory. however, it always needs the extension.
          userInput is created by me, File, StringBuffer, BufferReader
          are part of java.io */
          userInput fileinput = new userInput();
          String filename = fileinput.getUserInput("What is the file's name");
          File file = new File(filename);
          StringBuffer contents = new StringBuffer();
          BufferedReader reader = null;
          //try to read the data into reader
          try
               reader = new BufferedReader(new FileReader(file));
               String text = null;
               while((text = reader.readLine()) !=null)
                    //create a really big string, seems inefficient
                    contents.append(text).append(System.getProperty("line.separator"));
               //close the reader
               reader.close();
          catch (IOException e)
               System.out.println(e);
          //take the huge string and parse out all the carriage returns
          String[] stringtext = contents.toString().split("\\r");
          //create mmm to get take the individual string elements of stringtext
          String mmm;
          //create ccc to create the individual parsed array for the ArrayList
          String[] ccc = new String[2];
          //create the arraylist to store the data
          ArrayList<prices> data = new ArrayList<prices>();
          /*go through the carriage returned parsed array and feed the data elements
          into appropriate type into the arraylist, note the parse takes the eof as an
          empty cell*/
          //prices pricestamp = new prices();
          for(int c=0; c < stringtext.length-1; c++)
               prices pricestamp = new prices();
               mmm=stringtext[c];
               /*trims the extra text created by the carriage return, if it is not
               trimmed, the array thinks its got an element that is "" */
               mmm=mmm.trim();
               //whitespace split the array
               ccc=mmm.split("\\s");
               pricestamp.time=Integer.parseInt(ccc[0]);
               pricestamp.price=Double.parseDouble(ccc[1]);
               //System.out.println(ccc[1]);
               data.add(pricestamp);
               //System.out.println(data.get(c).price);
               //pricestamp.time=0;
               //pricestamp.price=0;
               pricestamp=null;
          //pricestamp=null;
          //System.out.println(pricestamp.price);
          System.out.println(data.size());
          double totalprice=0;
          for(int c=0; c<data.size(); c++)
               //System.out.println(data.get(c).price);
               totalprice+=data.get(c).price;
          System.out.println("This is the total price: " + totalprice);
public class prices
     int time;
     double price;
public class evenOdd
     public int isEven(double number)
          int evenodd;
          double half = number/2;
          int half2 = (int) half;
          if(half == half2)
               evenodd = 1;
          else
               evenodd = 0;
          return evenodd;
So the program works and does what I want it to do. I am very sure there are better ways to parse the data, but thats not my question. (For argument's sake lets assume the data that feeds this is pre-cleaned and is as perfect as baby in its mother's eyes). My question is actually something else. What I originally tried to do was the following:
prices pricestamp = new prices();
          for(int c=0; c < stringtext.length-1; c++)
               mmm=stringtext[c];
               mmm=mmm.trim();
               ccc=mmm.split("\\s");
               pricestamp.time=Integer.parseInt(ccc[0]);
               pricestamp.price=Double.parseDouble(ccc[1]);
               data.add(pricestamp);
however, when I did this, this part:
for(int c=0; c<data.size(); c++)
               //System.out.println(data.get(c).price);
               totalprice+=data.get(c).price;
          System.out.println("This is the total price: " + totalprice);
would only use the last price recorded in data. So each iteration was just the last price added to totalprice. I spent hours trying to figure out why and trying different ways of doing it to get it to work (as you probably can tell from random commented out lines). I am completely dumbfounded why it doesn't work the other way. Seems inefficient to me to keep creating an object (I think thats the right terminology, i equate this to dim in VB) and then clearing it, instead of just opening it once and then just overwriting it). I really would appreciate an explanation of what I am missing.
Thank you.
Rich

Answer 1

prices pricestamp = new prices();
for(int c=0; c < stringtext.length-1; c+)
mmm=stringtext[c];
mmm=mmm.trim();
ccc=mmm.split("\\s");
pricestamp.time=Integer.parseInt(ccc[0]);
pricestamp.price=Double.parseDouble(ccc[1]);
data.add(pricestamp);
}This is definitely wrong. You have only created one instance of pricestamp and you just keep overwriting it with new values. You need to put the new inside the loop to create a new instance for each row.
Also I doubt you really mean .length - 1, that doesn't include the last row.
Style wise:
Class names should always start with capital letters, fields and variable always with lower case letters. These conventions aren't imposed by the compiler but are established practice, and make your code a lot easier to follow. Use "camel case" to divide you names into words e.g. priceStamp
When using single letter names for integer indices people tend to expect i through n. This is a historical thing, dating back to FORTRAN.