Based on http://www.regular-expressions.info/creditcard.html This example includes test strings. This only validates the pattern, and not whether the credit card number passes a checksum validation. See the Luhn algorithm for details https://en.wikipedia.org/wiki/Luhn_algorithm...

regexp for year filtering

Extract jsfiddle links

this is the most perfect pattern I reach for url with query or anchor

Find single digits that are not part of an integer. For example, "27" should not match, but "27.1" will match the "1". "27.11" won't match.

Local variable and function parameter names should comply with a naming convention

Nickname validation. Only: letters _ One line. Tested with RoR

This expression converts any 3- or 4 digit timevalue to a value with colon between hours and minutes. So 345 is converted to 3:45 and 1500 is converted to 15:00

google.com:80 212.111.203.171 - - [02/Mar/2015:10:27:04 +0000] "GET /css/style.css HTTP/1.1" 304 138 "http://google.com" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.115 Safari/537.36"

ValidatesMathematical Expressions. Ignores whitespace. Includes parenthesis matching.

This allows to the programer to match the time format groups, in a way that allow to discard some parts of the format. E.g. I have a format HhMmSs and i want to ignore the 'Ss' part from the format when I have no Seconds