Generating large sets of random data vb6/vb net

Question

Is there an easy way in either language to generate a large set of random data quickly so far all the functions I've tried haven't worked too well when I need to generate a group of say 500,000 characters :( Any ideas?

Answer 1

Use UUIDGen. At least the chunks will be bigger.

Answer 2

Use UUIDGen.

Don't. GUIDs aren't really random. You can actually generate large amounts of data very fast using the System.Random class in VB.NET. 500,000 characters/bytes are no problem:

Dim buffer As Byte() = Nothing
Array.Resize(buffer, 500000)
Call New Random().NextBytes(buffer)
My.Computer.FileSystem.WriteAllBytes("filename", buffer, False)

This code takes considerably less than one second.

Answer 3

In VB6 the code would go something like this

Public Function FillRandomCol() as Collection
    Dim C As Collection
    Dim I As Long
    Set C = New Collection
    Randomize Timer
    For I = 1 To 500000
        C.Add RandomChar
    Next I
    Set FillRandomCol = C
End Sub

Public Function Random(ByVal Number As Integer) As Integer
    Random = CLng(Rnd * 1000000) Mod Number + 1
End Function

Public Function RandomChar() As String
    Const AlphaNum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    RandomChar = Mid$(AlphaNum, Random(36), 1)
End Function

Takes 1/2 second on a 2 Core Intel 2.40 GHz computer.