Download - The Bastards Book of Regular Expressions

Capture, Reuse 8805-14-8912-03-9803-15-9902-01-0007-07-0103-08-0201-22-12The reasoning was that it’s “obvious” that 98 refers to 1998 and 02 refers to 2002. Of course, it won’tbe so obvious as we get farther into the 21st century. So write a regex that coverts the two-digityears into four-digits:05-14-198912-03-199803-15-199902-01-200007-07-200103-08-200201-22-2012AnswerThis is a little bit tricky, not least of which because using a regex here is not recommended in reallife. If you’re working with a big dataset, you might have dates that include 1902 along with 2002.And so you don’t want to use a dumb regex to deal with that ambiguity, you’ll likely need to writea programming script with some logic and error-handling.However, sometimes you just need a quick and dirty solution if you know your data doesn’t containthose ambiguities. In this case, we’ll need to use two regex operations, one each for pre-2000 andpost-2000 dates.For pre-2000:Find ([89]\d)$Replace 19$1For post-2000:Find ([01]\d)$Replace 20$1Exercise