Tip of the Day

VB4/16
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Intermediate

Déjà Queue

You can use the technique for an "undo" menu/toolbar option. Use a collection instead of a listbox to reduce overhead. Support for both LIFO and FIFO is also included:

Public Queue As New Collection
Public Const Q_LIFO = 0
Public Const Q_FIFO = 1 

Public Sub Enqueue(QueueItem As Variant)
	Queue.Add QueueItem
End Sub 

Public Function Dequeue(Optional Mode As Long) As Variant 
	Dim Position as Long 

	If Queue.Count > 0 Then
		If Mode = Q_LIFO Then 
			Position = Queue.Count
		Else
			Position = 1 
		End If 
		Dequeue = Queue(Position)
		Queue.Remove Position
	Else
		Dequeue = Null
	End If
End Function

Brian Ray
Rockford, Illinois

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