Regular Expressions

string input = "My friend's Name is: Tia She lives in Argentina.";
Regex r = new Regex(@"Name is:\s([^\s]+).*$");
string name = r.Match(input).Groups[0].Value;

while (!(success = Try()));

public static Regex regex = new Regex(
      "\\<startstring\\>.*?\\<endstring\\>",
    RegexOptions.Singleline
    | RegexOptions.CultureInvariant
    | RegexOptions.Compiled
    );
...
    MatchCollection ms = regex.Matches(InputText);

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)