The Queue works like FIFO system. That is First In First Out, The item added in Queue is , first get out from Queue. We can Enqueue (add) items in Queue and we can Dequeue (remove from Queue ) or we can Peek (that is get the reference of first item added in Queue ) the item from Queue.

The commonly using functions are follows :

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object,_

	ByVal e As System.EventArgs) Handles Button1.Click

        Dim queueList As New Queue

        queueList.Enqueue("Sun")

        queueList.Enqueue("Mon")

        queueList.Enqueue("Tue")

        queueList.Enqueue("Wed")

        queueList.Enqueue("Thu")

        queueList.Enqueue("fri")

        queueList.Enqueue("Sat")

        MsgBox(queueList.Dequeue())

        MsgBox(queueList.Peek())

        If queueList.Contains("Sun") Then

            MsgBox("Contains Sun ")

        Else

            MsgBox("Not Contains Sun ")

        End If

    End Sub

End Class

When you execute the program it add seven items in the Queue. Then it Dequeue (remove) the oldest item from queue. Next it Peek() the oldest item from Queue (shows only , not remove ). Next it check the Item "Sun" contains in the Queue.

Enqueue : Add an Item in Queue

Syntax : Stack.Enqueue(Object)

Object : The item to add in Queue

Dequeue : Remove the oldest item from Queue (we dont get the item later)

Syntax : Stack.Dequeue()

Returns : Remove the oldest item and return.

Peek : Get the reference of the oldest item (it is not removed permenantly)

Syntax : Stack.Peek()

returns : Get the reference of the oldest item in the Queue

The following VB.NET Source code shows some of commonly used functions :