class

Regexp

v1_8_6_287 - Show latest stable - 4 notes - Superclass: Object

Document-class: Regexp

A Regexp holds a regular expression, used to match a pattern against strings. Regexps are created using the /.../ and %r{...} literals, and by the Regexp::new constructor.

Constants

IGNORECASE = INT2FIX(RE_OPTION_IGNORECASE)

EXTENDED = INT2FIX(RE_OPTION_EXTENDED)

MULTILINE = INT2FIX(RE_OPTION_MULTILINE)

Attributes

Show files where this class is defined (3 files)

re.c
lib/eregex.rb
lib/yaml/rubytypes.rb

February 10, 2009

3 thanks

Cheat Sheet

I have written a short introduction and a colorful cheat sheet for Perl Compatible Regular Expressions (PCRE) as used by Ruby’s Regexp class:

http://www.bitcetera.com/en/techblog/2008/04/01/regex-in-a-nutshell/

December 3, 2009 - (v1_8_6_287 - v1_8_7_72)

0 thanks

Testing Regular Expressions?

Writing regular expressions is never easy. You may use http://rubular.com to test and optimize your regular expressions.

March 8, 2010

0 thanks

Eagerness

Check out this simple example:

"Hello Ruby friend".sub(/^(.*)e/,  'X')  # => "Xnd"
"Hello Ruby friend".sub(/^(.*?)e/, 'X')  # => "Xllo Ruby friend"

The question mark turns the dotstar into non-eager mode which means it will halt on the first subsequent “e” rather than the last one. This comes in handy e.g. for Cucumber step definitions.

Okay, but not really nice:

/^I am using rvm "([^\"]*)" with gemset "(.*)"$/

Much more readable and consistent equivalent to the above:

/^I am using rvm "(.*?)" with gemset "(.*?)"$/

June 21, 2011

0 thanks

Loop through matches of your regular expression-based search

If you want to loop through the matches of a regular expression, String#scan is your friend. You can do something like this:

matches = '12345'.scan(/\d/)
matches.each do |m|
  puts m
end

# => 1
# => 2
# => 3
# => 4
# => 5

Regexp

Related

Constants

Attributes

Cheat Sheet

Testing Regular Expressions?

Eagerness

Loop through matches of your regular expression-based search