Pattern groups (...)
What is pattern group? What are pattern groups used for?
How to write a regular expression using groups to capture character names from the Ed, Edd 'n' Eddy animated comedy television series?
The grouping mechanism allows a part of a regex to be treated as a single unit. A group is represented by regular expression pattern enclosed in parentheses like this: (...).
Groups can be used to capture sub strings in a matched pattern. For example:
\D*(\d+).* # a group to capture the first string of digits \W*(\w+).* # a group to capture the first word
Groups can be used to limit a logical OR operation. For example:
(Mon|Sun)day.* # Excluding 'day.*' from the 'Mon|Sun' operation
Groups can also be nested to form a complex groups. For example:
house(cat(s|)|) # matches house, housecat or housecats
The regular expression to capture all Ed, Edd and Eddy is:
Ed(d(y|)|) (y|) - inner group to match 'y' or nothing (d(...)|) - outer group to match 'd(...)' or nothing
2013-01-23, 2106👍, 0💬
A free online regular expression test tool that allows to try you regular expression pattern and see...
All credit card numbers issued by Diners Club must start with 300 through 305, 36 or 38 and have 14 ...
How to perform a basic validation on email address using a regular expression? For example, "test+em...
All credit card numbers issued by MasterCard must start with 51 through 55 and have 16 digits. For e...
How to capture the Sogou web spider entries from Web log file? Here are some Web log file entries:12...