Correction of a code in vb.net

**Gefry** · 28-04-2009

I have started programming in VB just 1 an half months before but for implementing program logic I still have a problem, here I have a class called book shelf and books and classes which is to be a module sub main.

I have a box of execution during debugging which tells me: Object reference not set to an instance of an object.

C code is as follows:
class book

Code:

Public Class Book  
      Private _titre As String  
   
      Public Sub New ()  

      End Sub  

      Property title ()  
          Get  
              Return _titre  
          End Get  
          Set (ByVal value)  
              _titre = value  
          End Set  
      End Property  
  End Class

Class shelf:

Code:

 Public Class stager  
      Private t () As book a table books  
      As Integer Public nb  
      Dim j As Integer 'the number of books in the existing floor  

      Sub New ()  

      End Sub  

      Sub New (ByVal nombrlivre As Integer) 'the programmer chooses the number of books that may contain un stage  
          deliver = nb - 1  
          ReDim t (nb)  
          t (nb) = New Book  
      End Sub  
     
      Sub ajouter_livre (ByVal title As String)  

          If j <= nb Then we added provided that it not exceed the number of book that can hold the floor  
          T (j). Titr title = 'the program hangs here 
              j = j + 1  
          Else  
              Console.WriteLine ( "The floor is full")  
          End If  
      End Sub  
     
  End Class

How do i test the above program using a module whether this written code is working fine.

**RichiRich** · 28-04-2009

Hi,
Could you put your code between the tags code # step? It would be easier for everyone.
Maybe your problem is that t is not public, it is private.

Code:

 Private t () As book a table books

Hopefully this will help you.

**Timothi** · 28-04-2009

In the initialization of your shelf (new) assigning you a book that position 4:

Code:

Sunday stager1 As New shelf (4)

Code:

 Sub New (ByVal nombrlivre As Integer) 'the programmer chooses the number of books that may contain un stage 
          deliver = nb - 1  
          ReDim t (nb)  
          t (nb) = New Book  
      End Sub

here i have given some idea to you.

**Gefry** · 28-04-2009

yes, it is the solution I've found the right directly after sending my question and I have understood my fault it is that I have only the instantiated object table last case anyway thank you for your intervention.