A little stuck, need help =)

Question

Hey all, Im fairly new here and new to Java as well. I just started college this month and am moving along quite well but I kinda wrote myself into a wall if you will. I just finished writing a program to calculate commission based on some data the user inputs and have just found out that I need to output the total commissions they entered as well as the total value of the sales they entered. Well ive got the program written and now I need to figure out how to squeeze in a list. Ive attached my code so you guys can have a look. Any assistance is very much appreciated and I thank you in advance for any help you can give.
Thanks all,
Halfzipp
Brad.B
P.S. - I apologize if its a bit ugly as again I am a total noob to java.. well.. Ive got about 3 weeks of experience with it so far but thats only 2, 3 hour classes a week.. not enough imo but thats another story.. anyways, i digress, so here ya go.
// imports
import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.util.*;
import java.text.*;
// class
public class JavaAssignment3
     // main method
     public static void main(String[] args)
          //declare variables
          char commissionRateCode, continueCode1;
          double commission;
          double salePrice = 0.0;
          double commissionRate = 0.0;
          String commissionRateCode1; // user must choose either R, M or C
          String salePrice1, commission1, continueCodeString;
          boolean commissionRateCheck = true;
          boolean continueCode = true;
          boolean enterSalePrice = true;
          // create new scanner class to capture keyboard input
          Scanner keyboard = new Scanner(System.in);
          // display program title
          System.out.println("\t\t\t|#| Brad Bass |#|\n");
          System.out.println("\t    |#| Real Estate Commission Calculator |#|\n\n");
          // create while loop to take user back to price
          // input if they wish to calculate more commissions
          while (continueCode == true)
               /** //This is what screwed everything for me..
               //First, not having these 2 variables at all
               //and then Second, putting them here, Lol
               enterSalePrice = true;
               commissionRateCheck = true;
               {//main while loop
               //initiate the variables so the loop will run again
               enterSalePrice = true;
               commissionRateCheck = true;
               //create while loop to check if users input is a positive number
               while (enterSalePrice == true)
                    {//second while loop
                    //tell user to input the sale price
                    System.out.print("Enter the property's selling price: ");
                    //grab sale price from keyboard
                    salePrice1 = keyboard.nextLine();
                    //convert to a double
                    salePrice = Double.parseDouble(salePrice1);
                    //blank space for looks
                    System.out.println();
                    //if the price is zero or negative
                    //tell them to enter a positive number
                    if (salePrice <= 0.0)
                         //tell them to enter a positive number
                         System.out.println("You must enter a positive number.\n");
                    else
                         //if the number is valid continue program
                         enterSalePrice = false;
                    }//second while loop
                    //if they do Not enter the correct code,
                    //ask them to input the code again
                    while (commissionRateCheck == true)
                         {//third while loop
                         //ask user to input commission code and show them the choices
                         System.out.println("\nEnter the property code according to the following:\n\n" +
                                             "\tResidential" + "\t\t" + "enter R\n" +
                                             "\tMulti-Dwelling" + "\t\t" + "enter M\n" +
                                             "\tCommercial" + "\t\t" + "enter C\n");
                         //give the user a spot to enter the code
                         System.out.print("Choose your code: ");
                         //grab code as a string
                         commissionRateCode1 = keyboard.nextLine();
                         //convert to char
                         commissionRateCode = commissionRateCode1.charAt(0);
                         //extra line to keep things looking good
                         System.out.println();
                         // create switch statement to find commission rate
                         switch (commissionRateCode)
                              case 'R':
                              case 'r':
                                   commissionRate = 0.07;
                                   commissionRateCheck = false;
                              break;
                              case 'M':
                              case 'm':
                                   commissionRate = 0.06;
                                   commissionRateCheck = false;
                              break;
                              case 'C':
                              case 'c':
                                   commissionRate = 0.035;
                                   commissionRateCheck = false;
                              break;
                              //tell the user if they enter the wrong code and what the choices are
                              default:
                                   System.out.println("Code must be either - R, M or C!");
                         }//third while loop
                    //calculate commission using calcCommission method
                    commission = calcCommission(salePrice, commissionRate);
                    //format the double so it only displays 2 decimal points
                    String fmt = "0.00#";
                    DecimalFormat df = new DecimalFormat(fmt);
                    String finalCommission = df.format(commission);
                   //output users commission
                   System.out.println("Your commission is $" + finalCommission + "\n");
                   //ask if user would like to enter more commissions
                   System.out.print("More commissions? (y/n): ");
                   //grab thier answer as a string
                   continueCodeString = keyboard.nextLine();
                   //convert to a char
                   continueCode1 = continueCodeString.charAt(0);
                    //extra line to keep it looking good
                   System.out.println();
                   //if customer wants to continue, set continueCode = true,
                   if (continueCode1 == 'y')
                         continueCode = true;
                    //else set continueCode = false and exit the loop
                    else if (continueCode1 == 'n')
                         continueCode = false;
                    }//main while loop
                    //toss program in the garbage.... collector
                    System.gc();
               }//main
     // create second method to calculate commission
     public static double calcCommission(double salePriceA, double commissionRateA)
          // declare variables
          double commission;
          // calculate commission -> commission = salePrice * commissionRate
          commission = (double)salePriceA * (double)commissionRateA;
          // return results
          return commission;
     }//class

Answer 1

paulcw wrote:
The right way would be to create a class called, say, Sale, and Sale would have fields for sale price and commission (and probably other stuff relevant to a sale as well). Before the loop, you could declare a java.util.List of sale objects, like this:
List<Sale> sales = new ArrayList<Sale>();Then in your loop, after you get a sale price and a commission, you'd create a Sale object, and add the object to the list, like this:
sales.add(sale);Then after the main loop finished you could loop through this list, and add up values, etc.
It would also make sense to move stuff like the method that calculates commissions, into the Sale class, but that might not be part of your assignment.Sweet, thanks so much and ya know I definitely should have just read a bit more because just before I read your reply I found ArrayList in the API and added the following to my code:
          //create an array for the salePrice
          ArrayList a = new ArrayList( 100 );
          Collection threadSafeList = Collections.synchronizedCollection( a );
          //create an array for the commissions
          ArrayList b = new ArrayList( 100 );
          Collection threadSafeList2 = Collections.synchronizedCollection( b );right at the top with the other variables and near the bottom, just before i exit the main loop i added:
                    //add elements to the arrays
                    a.add(commission);
                    b.add(salePrice);
                    //test if its working
                    System.out.println(a);
                    System.out.println(b);so that is all working now and I must admit I feel a bit silly for having posted this but then again I guess it did get me to stay up and keep searching hehe.
Now I just need to sum the elements in the arrayList, after the user chooses to end. My concern is, how are these elements being stored in the array? I assume they are getting stored as Strings so if thats the case could I declare the arrayList as an array of doubles? or would I have to parse the data and then add it all.. Or, is there an easy to use method like ArrayList.sum() or something to that affect.. Im searching as I write this but ya never know.
Thanks again for your help.
Take it easy,
Brad.B
EDIT:
Ok so from my reading it seems Im going to need to convert my arrayList to an array and then I can sum the elements. The code would look something like this:
// get array
Object c[] = a.toArray();
double sum = 0.0;
// sum the array
for(double i=0.0; i<c.length; i++)
sum += ((Double) c).doubleValue();
System.out.println("Sum is: " + sum); altho I could be totally wrong.. it is 4 am and I can barely see straight but I cant stop...  I must... get... this ... done... =P
Edited by: halfzipp on Jan 29, 2008 2:05 AM
Edited by: halfzipp on Jan 29, 2008 2:10 AM