Close but help would be grateful

[reader34]

Hey guys i am learning java at college and i have a task to do.. basically my task is to create a airline booking system, this consists of:

Please select from the following options:

1- Book a luxury seat.
2 Book an executive seat.
3- Display seats/availability
4- Exit

Now the code can book a luxury seat ( though i have only created one for the timebeing). When I enter in two types of information from two different customers, I press option 2 and it asks for name( I want the name to find the name that was entered before binded to that seat) It will throw a wobbley saying " NullpointerException:null" at the if (tks [ count] = 0; count < ticketTot; count ++. I think i know why this is happening because its trying to show a int but its a String and its that what I want to show a String, is there anyway of getting around this problem?
Reader34

import java.util.Scanner;
class Libary 
{
        static final  int quit = 0;
        
            public static int getMenuOpt()
            {
                 
                
                Scanner menuOpt = new Scanner (System.in);
                int option;
                
                System.out.println("Welcome to CCN jet");
                System.out.println("Please select a option below.");
               
                   System.out.println("------------------------------");
                    System.out.println("1.Book a luxury seat");
       
                   System.out.println("2. list bookings ");
          
                 
                            System.out.println(quit + ".Quit");
                            
                            option  = menuOpt.nextInt();
                            return option;
                            
                        }
                        
                        public static int addTicket (Ticket tks [], int ticketTot)
                        {
                            Scanner input = new Scanner (System.in);
                            String name;
                            String seatClass;
                   
              
                      
                            
                          
                           System.out.println("You have chosen to luxury");
                
                        
                               
                            System.out.print ("Enter your name ");
                            name = input.nextLine();
                            System.out.print("Please comfirm booking type , Enter Luxury");
                            seatClass = input.nextLine();
                        
                           
                            
                            System.out.println("thank you your details are :"+ name + seatClass );
                            tks [ticketTot] = new Ticket( name, seatClass);
                            ticketTot++;
                            return ticketTot;      
                            
                           
                            
                            

                            
               
                            
                        }
                           
                        public static void listByName (Ticket tks [], int ticketTot)
                        {
                            
                            
                            Scanner input = new Scanner (System.in);
                          
                            String name;
                            String seatClass;
                            System.out.print("Enter your name");
                            name = input.next();
                            
                            for  ( int count = 0 ; count < ticketTot;  count ++ )
                            {

                                System.out.println( tks [count].getName ());
                                System.out.println(tks [count].getSeatClass ());
                                
                                   
                                    

                                            
                                      
                                    }
                           
         
                            }
                            public static void main (String [] args)
                            {
                               
                               Scanner input = new Scanner (System.in);
                                

                           
                                Ticket tickets [] = new Ticket [5]; 
                            
                        
                                int ticketsInLibrary = 1;
                                int option;
                                int seatsInLibrary=1;
                              
                                
                                
                                
                                option = getMenuOpt();
                                
                               
                 
                                
                                while (option != quit)
                                {
                                    if (option == 1)
                                        ticketsInLibrary = addTicket (tickets, ticketsInLibrary );
                                        
                                        
                              
                                        
                                      if (option == 2 )
                                       
                                        
                                        listByName ( tickets, seatsInLibrary);
                                            System.out.println(" Seat number " + seatsInLibrary++  );
                                      
                                            
                                      
                                                
                                       
                       
                                         
                                            
                                            option = getMenuOpt();
                                        }

                                    }

                                }


                                    
                                           
                                
                                
                                
                            
                            
                            
import java.util.Scanner;

class Ticket
{
        
    
            private String name;
            private String seatClass;

            
           
       
            
        
            
            Ticket ( String  n, String s)
            {
                
                name = n;
                seatClass = s;

              
                
             

            }
            
                        
                String getName ()
                {
                    return name;
                    
                }
                
                String  getSeatClass()
                
                { return seatClass;
                    
                }
                
              
                }

[Eranga]

Can you bit clear it up?

Do you want to convert a string into an int to fix this problem? How can NullPointerException solve by that? It's better if you can copy-paste here full error message and the inputs you used.

[mtyoung]

Array index start from 0, not 1....
how can you add ticket to index 1 and remain index 0 as null?

[Eranga]

Seems you are dig into that long code. ;)

[mtyoung]

Practice only

[Eranga]

Practice only

Excellent, i like that way.

[reader34]

Ahhh thanks i changed both my values in the array from = 1 to = 0 and now when i enter in a name of someone who has booked a ticket there name type and seat number comes up. I have one question if anybody doesn't mind helping? I want to show a user how many seats are left and taken, would i use some sort of loop to do this? like count every seat and then show whats left.
thanks
reader34

[Eranga]

I hope you have all details about seats on a collection, array, list or anything...

[CJSLMAN]

You can use an array to keep track of the seats. Since you're using arrays in your code, I'll assume you know the basics and don't need a tutorial, but here's the Array API so you can see all the methods that can be used:
Array (Java Platform SE 6)
Luck,
CJSL