Generate a random string

S

SIMIN

Regular
Joined
Mar 10, 2008
Messages
92
Hi,
I wanna generate a random alphanumeric in the following format:

d4g2o5m3-u1q2-s7z9-z6o8-o3q2c2m5m2s9

So with your help, I wrote a public function like this:
Visual Basic: 
Public Function GenerateContactID() As String
    Dim MyRandom As New Random
    GenerateContactID = Nothing
    For MyLoop As Integer = 1 To 8
        If MyLoop Mod 2 = 1 Then
            GenerateContactID = GenerateContactID + Convert.ToChar(MyRandom.Next(97, 123))
        End If
        If MyLoop Mod 2 = 0 Then
            GenerateContactID = GenerateContactID + MyRandom.Next(1, 10).ToString
        End If
    Next
    GenerateContactID = GenerateContactID + "-"
    For MyLoop As Integer = 1 To 4
        If MyLoop Mod 2 = 1 Then
            GenerateContactID = GenerateContactID + Convert.ToChar(MyRandom.Next(97, 123))
        End If
        If MyLoop Mod 2 = 0 Then
            GenerateContactID = GenerateContactID + MyRandom.Next(1, 10).ToString
        End If
    Next
    GenerateContactID = GenerateContactID + "-"
    For MyLoop As Integer = 1 To 4
        If MyLoop Mod 2 = 1 Then
            GenerateContactID = GenerateContactID + Convert.ToChar(MyRandom.Next(97, 123))
        End If
        If MyLoop Mod 2 = 0 Then
            GenerateContactID = GenerateContactID + MyRandom.Next(1, 10).ToString
        End If
    Next
    GenerateContactID = GenerateContactID + "-"
    For MyLoop As Integer = 1 To 4
        If MyLoop Mod 2 = 1 Then
            GenerateContactID = GenerateContactID + Convert.ToChar(MyRandom.Next(97, 123))
        End If
        If MyLoop Mod 2 = 0 Then
            GenerateContactID = GenerateContactID + MyRandom.Next(1, 10).ToString
        End If
    Next
    GenerateContactID = GenerateContactID + "-"
    For MyLoop As Integer = 1 To 12
        If MyLoop Mod 2 = 1 Then
            GenerateContactID = GenerateContactID + Convert.ToChar(MyRandom.Next(97, 123))
        End If
        If MyLoop Mod 2 = 0 Then
            GenerateContactID = GenerateContactID + MyRandom.Next(1, 10).ToString
        End If
    Next
End Function
However, sometimes the call to this function will return the same result, I mean it's not completely random?
How that's possible?
Thank you :)
 
Last edited:
Not properly tested but I would have written it as
Visual Basic: 
    Dim r As New Random

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim GenerateContactID As String = String.Empty

        For MyLoop As Integer = 1 To 8
            If MyLoop Mod 2 = 1 Then
                GenerateContactID &= Convert.ToChar(r.Next(97, 122))
            Else
                GenerateContactID &= r.Next(0, 9).ToString()
            End If
        Next
        Debug.WriteLine(GenerateContactID)
    End Sub

Although things like CInt etc. are perfectly valid in .Net I tend to avoid them simply because I use both C# and VB.Net and remembering two ways to do things is twice the effort of remembering one way ;)
 
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