Linked List

Ordered linked list.

BET_ListItem class

Private TheValue As Variant 
Private NextNode As BET_ListItem 

BET_LinkedList class

Private head As BET_ListItem 

Public Sub Add(value As Variant) 
Dim node As BET_ListItem 
Dim lCurrent As BET_ListItem 
Dim lPrevious As BET_ListItem 
        
   Set node = New BET_ListItem 
   node.TheValue = value 

   all Fun_Search(value, lCurrent, lPrevious) 

   Set node.NextNode = head 
   Set head = node 
End Sub 

Public Sub Remove(value As Variant) 
Dim node As BET_ListItem 
Dim prev As BET_ListItem 
    
    Set node = head 
    While Not node Is Nothing 
        If node.TheValue = value Then 
            'remove node
            If node Is head Then 
                Set head = node.NextNode 
            Else 
                Set prev.nextNode = node.NextNode 
            End If 
            Exit Sub 
        End If 
        Set prev = node 
        Set node = node.NextNode 
    Wend 
End Sub 

Public Function Exists(value As Variant) As Boolean 
Dim node As BET_ListItem 
    
    Set node = head 
    While Not node Is Nothing 
        If node.TheValue = value Then 
            Exists = True 
            Exit Function 
        End If 
        Set node = node.NextNode 
    Wend 
End Function 

Public Function Count() As Long 
Dim node As BET_ListItem 
    
    Set node = head 
    While Not node Is Nothing 
        Count = Count + 1 
        Set node = node.NextNode 
    Wend 
End Function 

Private Function Fun_Search(ByVal varItem As Variant, 
                            ByRef lCurrent As BET_ListItem, _ 
                            ByRef lPrevious As BET_ListItem) 
Dim bFound As Boolean 
   bFound = False 
   Set lPrevious = Nothing 
   Set lCurrent = _Head 

   Do While Not lCurrent Is Nothing 
      If (varItem > lCurrent.Value) Then 
         Set lPrevious = lCurrent 
         Set lCurrent = lCurrent.NetItem 
      Else 
         Exit Do 
      End If 
   Loop 

   If Not (lCurrent Is Nothing) Then 
      bFound = (lCurrent.Value = varItem) 
   End If 
   Search = bFound 
End Function 

Private Function Delete() 

End Function 

Sample

Public Sub Testing_LinkedList() 
Dim myLinkedList As BET_LinkedList 
   Set myLinkedList = New BET_LinkedList 
   myLinkedList.Add("Mon") 
   Debug.Print myLinkedList.Count 
   myLinkedList.Add("Tue") 
   myLinkedList.Add("Wed") 
   Debug.Print myLinkedList.Exists("Tue") 
   myLinkedList.Remove("Tue") 
End Sub