Results for: "match"

Converts pattern to a Regexp (if it isn’t already one), then invokes its match method on str. If the second parameter is present, it specifies the position in the string to begin the search.

'hello'.match('(.)\1')      #=> #<MatchData "ll" 1:"l">
'hello'.match('(.)\1')[0]   #=> "ll"
'hello'.match(/(.)\1/)[0]   #=> "ll"
'hello'.match(/(.)\1/, 3)   #=> nil
'hello'.match('xx')         #=> nil

If a block is given, invoke the block with MatchData if match succeed, so that you can write

str.match(pat) {|m| ...}

instead of

if m = str.match(pat)
  ...
end

The return value is a value from block execution in this case.

Returns a MatchData object describing the match, or nil if there was no match. This is equivalent to retrieving the value of the special variable $~ following a normal match. If the second parameter is present, it specifies the position in the string to begin the search.

/(.)(.)(.)/.match("abc")[2]   #=> "b"
/(.)(.)/.match("abc", 1)[2]   #=> "c"

If a block is given, invoke the block with MatchData if match succeed, so that you can write

/M(.*)/.match("Matz") do |m|
  puts m[0]
  puts m[1]
end

instead of

if m = /M(.*)/.match("Matz")
  puts m[0]
  puts m[1]
end

The return value is a value from block execution in this case.

Returns sym.to_s.match.

The first form returns the MatchData object generated by the last successful pattern match. Equivalent to reading the special global variable $~ (see Special global variables in Regexp for details).

The second form returns the nth field in this MatchData object. n can be a string or symbol to reference a named capture.

Note that the last_match is local to the thread and method scope of the method that did the pattern match.

/c(.)t/ =~ 'cat'        #=> 0
Regexp.last_match       #=> #<MatchData "cat" 1:"a">
Regexp.last_match(0)    #=> "cat"
Regexp.last_match(1)    #=> "a"
Regexp.last_match(2)    #=> nil

/(?<lhs>\w+)\s*=\s*(?<rhs>\w+)/ =~ "var = val"
Regexp.last_match       #=> #<MatchData "var = val" lhs:"var" rhs:"val">
Regexp.last_match(:lhs) #=> "var"
Regexp.last_match(:rhs) #=> "val"

Returns the pre-match

s = StringScanner.new('test string')
s.scan(/\w+/)           # -> "test"
s.scan(/\s+/)           # -> " "
s.pre_match             # -> "test"
s.post_match            # -> "string"

Returns the post-match

s = StringScanner.new('test string')
s.scan(/\w+/)           # -> "test"
s.scan(/\s+/)           # -> " "
s.pre_match             # -> "test"
s.post_match            # -> "string"

Returns the portion of the original string before the current match. Equivalent to the special variable $`.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.pre_match   #=> "T"

Returns the portion of the original string after the current match. Equivalent to the special variable $'.

m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie")
m.post_match   #=> ": The Movie"

Matches addr against this entry.

Matches addr against each ACLEntry in this list.

Completion for hash key.

Returns an array of nodes matching a given XPath.

Matches this template against tuple. The tuple must be the same size as the template. An element with a nil value in a template acts as a wildcard, matching any value in the corresponding position in the tuple. Elements of the template match the tuple if the are == or ===.

Template.new([:foo, 5]).match   Tuple.new([:foo, 5]) # => true
Template.new([:foo, nil]).match Tuple.new([:foo, 5]) # => true
Template.new([String]).match    Tuple.new(['hello']) # => true

Template.new([:foo]).match      Tuple.new([:foo, 5]) # => false
Template.new([:foo, 6]).match   Tuple.new([:foo, 5]) # => false
Template.new([:foo, nil]).match Tuple.new([:foo])    # => false
Template.new([:foo, 6]).match   Tuple.new([:foo])    # => false

Matches this TemplateEntry against tuple. See Template#match for details on how a Template matches a Tuple.

Indicate if this NameTuple matches the current platform.

MatchData encapsulates the result of matching a Regexp against string. It is returned by Regexp#match and String#match, and also stored in a global variable returned by Regexp.last_match.

Usage:

url = 'https://docs.ruby-lang.org/en/2.5.0/MatchData.html'
m = url.match(/(\d\.?)+/)   # => #<MatchData "2.5.0" 1:"0">
m.string                    # => "https://docs.ruby-lang.org/en/2.5.0/MatchData.html"
m.regexp                    # => /(\d\.?)+/
# entire matched substring:
m[0]                        # => "2.5.0"

# Working with unnamed captures
m = url.match(%r{([^/]+)/([^/]+)\.html$})
m.captures                  # => ["2.5.0", "MatchData"]
m[1]                        # => "2.5.0"
m.values_at(1, 2)           # => ["2.5.0", "MatchData"]

# Working with named captures
m = url.match(%r{(?<version>[^/]+)/(?<module>[^/]+)\.html$})
m.captures                  # => ["2.5.0", "MatchData"]
m.named_captures            # => {"version"=>"2.5.0", "module"=>"MatchData"}
m[:version]                 # => "2.5.0"
m.values_at(:version, :module)
                            # => ["2.5.0", "MatchData"]
# Numerical indexes are working, too
m[1]                        # => "2.5.0"
m.values_at(1, 2)           # => ["2.5.0", "MatchData"]

Global variables equivalence

Parts of last MatchData (returned by Regexp.last_match) are also aliased as global variables:

• $~ is Regexp.last_match;

• $& is Regexp.last_match[0];

• $1, $2, and so on are Regexp.last_match[i] (captures by number);

• $` is Regexp.last_match.pre_match;

• $' is Regexp.last_match.post_match;

• $+ is Regexp.last_match[-1] (the last capture).

See also “Special global variables” section in Regexp documentation.