Imports System
Public Module Module1
Function isInAlphabeticalCharacters(ByVal s As String)
For i = 0 To s.Length - 1
If Not Char.IsLetter(s.Chars(i)) Then
Return False
End If
Next
Return True
End Function
Public Sub Main()
Dim s1 As String = "vb.net java c c++"
Console.WriteLine(isInAlphabeticalCharacters(s1))
Dim s2 As String = "abcxyz"
Console.WriteLine(isInAlphabeticalCharacters(s2))
End Sub
End Module
' run:
'
' False
' True
'