Here’s a quick-and-dirty method to determine whether a string contains only lowercase characters
' the string to test is in the SOURCE variableIf System.Text.RegularExpressions.Regex.IsMatch(source, "^[a-z]+$") Then Console.WriteLine("Lowercase string")End IfIf the source string can contain accented wovel, you should modify the regular expresson pattern to account for them as well
If System.Text.RegularExpressions.Regex.IsMatch(source, "^[a-z]àèéìòù+$") Then Console.WriteLine("Lowercase string")End IfIf you really want to test that the string doesn’t contain any uppercase character, that is, you want to check that you already have the lowercase version of the string, you can use another approach:
If String.Compare(source, source.ToLower) = 0 Then Console.WriteLine("Lowercase string")End If
