Imports System
Class Sample
Public Shared Sub Main()
Dim s1 As String = "abcd"
Dim s2 As String = ""
Dim s3 As String = Nothing
Console.WriteLine("String s1 {0}.", Test(s1))
Console.WriteLine("String s2 {0}.", Test(s2))
Console.WriteLine("String s3 {0}.", Test(s3))
End Sub 'Main
Public Shared Function Test(s As String) As [String]
If [String].IsNullOrEmpty(s) = True Then
Return "is null or empty"
Else
Return String.Format("(""{0}"") is not null or empty", s)
End If
End Function 'Test
End Class 'Sample