Imports System
Imports System.Linq
Public Class Program
Public Shared Sub Main()
Dim s As String = "ABC75DE8FG-J80-900C-21PO"
Dim result = From ch In s
Where Char.IsDigit(ch)
Select ch
Dim count As Integer = result.Count()
Console.WriteLine(count)
End Sub
End Class
' run:
'
' 10
'