Regular Expressions

Peter_in_2780 wrote:

You'd be pushing it uphill with a sharp stick to write a regex to validate the check digit

Input: TFN '123456782'
Regex: ^TFN\s*(')?(?<number>\d{3}\s*\d{3}\s*\d{3})(')?\s*$

TFN '123456782'
TFN'123 456 782'
TFN123456782
TFN 123 456 782

^    Start of the string
$    End of the string
\s*  Consumes 0 or more white space characters. It will make sure you match TFN123 and TFN    123
(')? Optional quotation mark
(?<number> ...) Named group, makes it easier to extract the actual number

\b

Member 13555386 wrote:

TFN includes a check digit for detecting erroneous numbers. ... Can it be done?

Member 13555386 wrote:

(\d{8,9})|(\d\d\d[ ]\d\d\d[ ]\d\d\d)|(\d\d\d[-]\d\d\d[-]\d\d\d)

(\d{8,9})|(\d\d\d[- ]\d\d\d[- ]\d\d\d)

\[CameraDefinition\.(?<CamNumber>\d+)\]\r\nTitle\=(?<Title>.*)\r\nGuid\=(?<Guid>\{[0-9A-Fa-f\-]*\})

\[CameraDefinition\.(?<CamNumber>\d+)\]\r\n(.*\r\n)Guid\=(?<Guid>\{[0-9A-Fa-f\-]*\})\r\n{1,}

Sonhospa wrote:

no capture if there are more lines between ...

Dim\s+(?<variable_name>\w_\w_\w+_(?<expected_type>\w+)_\w+)\s+As\s+(?:(?<matched_type>\2)|(?<mismatched_type>\w+))

Dim L_V_Scalar_Integer_Item As Integer

expected_type   matched_type   mismatched_type
Integer         Integer

Dim L_V_Scalar_Integer_Item As String

expected_type   matched_type   mismatched_type
Integer                        String

Match m = Regex.Match("Dim L_V_Scalar_Integer_Item As String", 
"Dim\s+(?<variable_name>\w_\w_\w+_(?<expected_type>\w+)_\w+)\s+As\s+(?:(?<matched_type>\2)|(?<mismatched_type>\w+))");
if (m.Success)
{
    // For example, check if the group named 'matched_type' is empty
    // This means that there is a violation of the naming convention
    if (String.IsNullOrEmpty(m.Groups["matched_type"].Value))
    {
        string errorText = String.Format(@"The type '{0}' is not allowed for variable name '{1}'. 
        The correct type is '{2}'", 
        m.Groups["mismatched_type"].Value,
        m.Groups["variable_name"].Value,
        m.Groups["expected_type"].Value);
    }
}
else
{
    // Do some error handling for a failed match
}