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POWhy is the stored value always erased in my program
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  1. POWhy is the stored value always erased in my program
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    copied!<p>Ok, so I'm trying to finish our simple project for Data Strcutures but there is always some error that just keep showing up on my program. I have fixed some of them but there is this one that makes me want to give up. Maybe you guys could help me find the solution?</p> <p>Here is my code (class LogInSystem):</p> <pre><code> // NMQ import java.util.ArrayList; import java.util.Scanner; import java.util.Vector; public class LogInSystem { private static final int MAX_SEATS = 10; Vector&lt;String&gt; username = new Vector&lt;String&gt;(); ArrayList&lt;String&gt; password = new ArrayList&lt;String&gt;(); int p; String Username, Password, rUsername, rPassword; private Scanner input = new Scanner(System.in); public LogInSystem() { loginScreen(); } private void loginScreen() { boolean done = false; do { printMainMenu(); int choice = getMainMenuChoice(); switch (choice) { case 1: // Log In logIn(); break; case 2: // To Register register(); break; case 3: // Exit done = true; break; } } while (!done); } //Registration private void register() { System.out.println("Input a Username"); Username = input.next(); System.out.println("Input a Password"); Password = input.next(); System.out.println("... Registered!"); } //Log In private void logIn() { p = 0; System.out.println("Input a Username"); rUsername = input.next(); System.out.println("Input a Password"); rPassword = input.next(); // If the log in is successful it will got to the next menu if(rUsername.equals(Username)&amp;&amp; rPassword.equals(Password)) { System.out.println("... Logging In"); boolean done = false; String[] seats = new String[MAX_SEATS]; // the item list initializeItems(seats); // Printing of 2nd menu do { printMainMenu2(); int choice = getMainMenuChoice2(); // choice off of the main menu switch (choice) { case 1: // Adding Seat addSeat(seats); break; case 2: // Viewing Seat List viewSeatList(seats); break; case 3: // Exit done = true; break; } } while (!done); } else System.out.println("Invalid log in, please try again."); } private int getMainMenuChoice() { int choice; // choice entered boolean valid = false; // is choice valid? do { System.out.print("&gt;&gt;&gt;&gt;&gt; "); choice = cineplexError.readInt(); if (1 &lt;= choice &amp;&amp; choice &lt;= 4) { valid = true; } else { System.out.println("Invalid choice."); } } while (!valid); return choice; } private void printMainMenu() { System.out.println("\nMain Menu\n"); System.out.println("Press 1 to Log In"); System.out.println("Press 2 to Register"); System.out.println("Press 3 to Exit"); System.out.println(); } public static void main(String[] args) { new LogInSystem(); } int getMainMenuChoice2() { int choice; // choice entered boolean valid = false; // is choice valid? do { System.out.print("&gt;&gt;&gt;&gt;&gt; "); choice = cineplexError.readInt(); if (1 &lt;= choice &amp;&amp; choice &lt;= 4) { valid = true; } else { System.out.println("Invalid choice."); } } while (!valid); return choice; } void printMainMenu2() { System.out.println("\nMain Menu\n"); System.out.println("Press 1 to Reserve a Seat"); System.out.println("Press 2 to View the Seat List"); System.out.println("Press 3 to Exit Buying"); System.out.println(); } void initializeItems(String[] seats) { for (int i = 0; i &lt; seats.length; i++) { seats[i] = ""; } } void addSeat(String[] seats) { int seatIndex = findEmptySeatList(seats); // index of first empty item list if (seatIndex == seats.length) { System.out.println("Seat is already occupied. Sorry."); } else { String seat = getSeatName(); // seat's name seats[seatIndex] = seat; System.out.println(seat + " is on seat list #" + (seatIndex + 1)); } } int findEmptySeatList(String[] seat) { for (int i = 0; i &lt; seat.length; i++) { if (isEmpty(seat, i)) { return i; } } return seat.length; } boolean isEmpty(String[] seats, int seatIndex) { return seats[seatIndex].equals(""); } String getSeatName() { System.out.print("Enter the name of reservator: "); return cineplexError.readString(); } void viewSeatList(String[] seats) { System.out.println("\nSeat List\n"); for (int i = 0; i &lt; seats.length; i++) { System.out.println((i + 1) + ". " + seats[i]); } } } </code></pre> <p>Here is the other class (cineplexError):</p> <pre><code>// NMQ import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class cineplexError { private static BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); private static String integerReprompt = "Invalid integer. Try again: "; private static String doubleReprompt = "Invalid double. Try again: "; private static String charReprompt = "Invalid character. Try again: "; public static String readString() { String s = null; try { s = in.readLine(); } catch (IOException ex) {} return s; } public static char readChar() { char c = 0; String s = null; try { s = in.readLine(); } catch (IOException ex) {} if (s.length() == 1) { c = s.charAt(0); // valid = true; } else { System.out.print(charReprompt); } return c; } public static int readInt() { int i = 0; boolean valid = false; try { i = Integer.parseInt(in.readLine()); } catch (IOException ex) { System.out.print(integerReprompt); } valid = true; return i; } public static double readDouble() { double d = 0.0; boolean valid = true; try { d = Double.parseDouble(in.readLine()); } catch (IOException ex) {} valid = true; valid = false; System.out.print(doubleReprompt); return d; } public void pause() { System.out.print("Press enter to continue..."); try { in.readLine(); } catch (IOException ex) {} } public static void setIntegerReprompt(String prompt) { integerReprompt = prompt; } public void setDoubleReprompt(String prompt) { doubleReprompt = prompt; } public void setCharReprompt(String prompt) { charReprompt = prompt; } } </code></pre> <hr> <p>The bug in the program is that whenever I reserve a seat and log out and log in again the name of the reservator or the name of the one that reserves a seat is being erased when I view the seat list. Should I put a control statement that makes the value stored permanently? Can you help me out? Thanks.</p>
 

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