Imports System.Text.RegularExpressions
Module Module1
Sub Main()
Dim s1 As String = "VBNET13Java89Python"
Console.WriteLine(Regex.IsMatch(s1, "^[a-z]*$"))
Dim s2 As String = "!**!***!"
Console.WriteLine(Regex.IsMatch(s2, "^[a-z]*$"))
Dim s3 As String = "VB 13 Java 89 Python"
Console.WriteLine(Regex.IsMatch(s3, "^[a-z]*$"))
Dim s4 As String = "VBJavaPython"
Console.WriteLine(Regex.IsMatch(s4, "^[a-z]*$"))
Dim s5 As String = "vbjavapython"
Console.WriteLine(Regex.IsMatch(s5, "^[a-z]*$"))
End Sub
End Module
' run:
'
' False
' False
' False
' False
' True