<xmp>UNKNOWN
    //**************************************
    // Name: Using Yield Keyword
    // Description:Four examples of using yield Keyword in VB .Net 2012
    // By: Salem Al Shekaili
    //
    //
    // Inputs:None
    //
    // Returns:None
    //
    //Assumes:None
    //
    //Side Effects:None
    //This code is copyrighted and has limited warranties.
    //Please see http://www.Planet-Source-Code.com/xq/ASP/txtCodeId.9098/lngWId.10/qx/vb/scripts/ShowCode.htm
    //for details.
    //**************************************
    
    Module Module1
    Sub Main()
    
    //     'example 1
    ShowingFiles()
    //     'example 2
    Oddnumber()
    //     'example 3
    prime()
    //     'example 4
    Some_number()
    Console.ReadKey()
    End Sub
    Private Sub prime()
    For Each numbers As Long In PrimesNumber(50)
    Console.WriteLine(numbers.ToString() + Environment.NewLine)
    Next
    End Sub
    //     'example 4
    Private Sub Some_number()
    For Each number As Integer In SomeNumbers()
    Console.Write(number & " ")
    Next
    End Sub
    Private Sub ShowingFiles()
    For Each file_Name In FileToProcessIterator()
    //     ' Do something; process file
    Console.WriteLine(file_Name)
    Next
    End Sub
    Private Iterator Function FileToProcessIterator() As IEnumerable(Of String)
    For Each file_Name In System.IO.Directory.EnumerateFiles("c:\", "*.*")
    Yield file_Name
    Next
    End Function
    Public Iterator Function ReturnTenThings10() As IEnumerable(Of String)
    Dim Ret As New List(Of String)()
    For I As Integer = 0 To 9
    Threading.Thread.Sleep(1000)
    Yield (I + 1).ToString()
    Next
    End Function
    Private Iterator Function SomeNumbers() As System.Collections.IEnumerable
    Yield 3
    Yield 5
    Yield 8
    End Function
    Private Iterator Function CityNames() As System.Collections.IEnumerable
    Dim str As String() = {"Abu Dhabi", "Londan", "Dubai", "Sharjah", "Ras Al kymah"}
    For i As Integer = 0 To str.Length - 2
    Yield str(i) & " City "
    Next
    End Function
    Private Sub Oddnumber()
    For Each strCity As String In CityNames()
    System.Console.Write(strCity & " ")
    Next
    End Sub
    'This below function shows how to find a
    //     number's prime factors in Visual Basic .
    //     NET.
    Private Iterator Function PrimesNumber(num As Integer) As IEnumerable(Of Long)
    Dim isPrime As Boolean = False
    //     ' Take out the 2s.
    For i As Integer = 2 To num
    isPrime = False
    If i = 2 Then
    Yield i
    Continue For
    End If
    ' We don't care about even numbers (exce
    //     pt 2)
    If i Mod 2 = 0 Then
    Continue For
    End If
    isPrime = True
    For j As Integer = 2 To CLng(Math.Sqrt(i))
    ' Check if current value is divisible by
    //     something
    //     ' other than 1 and itself
    If i Mod j = 0 Then
    isPrime = False
    Exit For
    End If
    Next
    If isPrime Then Yield i
    Next
    End Function
    End Module

		</xmp>