With no argument, returns the value of $!
, which is the result of the most recent pattern match (see Regexp global variables):
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match # => #<MatchData "cat" 1:"a"> /a/ =~ 'foo' # => nil Regexp.last_match # => nil
With non-negative integer argument n
, returns the _n_th field in the matchdata, if any, or nil if none:
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match(0) # => "cat" Regexp.last_match(1) # => "a" Regexp.last_match(2) # => nil
With negative integer argument n
, counts backwards from the last field:
Regexp.last_match(-1) # => "a"
With string or symbol argument name
, returns the string value for the named capture, if any:
/(?<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" Regexp.last_match('foo') # Raises IndexError.
See as_json
.
Returns an array of values from self
.
With integer arguments integers
given, returns an array containing each value given by one of integers
:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.values_at(0, 2) # => ["Joe Smith", 12345] joe.values_at(2, 0) # => [12345, "Joe Smith"] joe.values_at(2, 1, 0) # => [12345, "123 Maple, Anytown NC", "Joe Smith"] joe.values_at(0, -3) # => ["Joe Smith", "Joe Smith"]
Raises IndexError
if any of integers
is out of range; see Array Indexes at Array
.
With integer range argument integer_range
given, returns an array containing each value given by the elements of the range; fills with nil
values for range elements larger than the structure:
joe.values_at(0..2) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(-3..-1) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(1..4) # => ["123 Maple, Anytown NC", 12345, nil, nil]
Raises RangeError
if any element of the range is negative and out of range; see Array Indexes at Array
.
Equivalent to self.to_s.start_with?
; see String#start_with?
.
Return the path as a String
.
to_path
is implemented so Pathname
objects are usable with File.open
, etc.
Returns true for IPv4 private address (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). It returns false otherwise.
Returns true for IPv4-compatible IPv6 address (::/80). It returns false otherwise.
Returns the socket path as a string.
Addrinfo.unix("/tmp/sock").unix_path #=> "/tmp/sock"
Returns the size of the most recent match in bytes, or nil
if there was no recent match. This is different than matched.size
, which will return the size in characters.
s = StringScanner.new('test string') s.check /\w+/ # -> "test" s.matched_size # -> 4 s.check /\d+/ # -> nil s.matched_size # -> nil
Returns the pre-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the post-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the subgroups in the most recent match at the given indices. If nothing was priorly matched, it returns nil.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.scan(/(\w+) (\w+) (\d+) /) # -> "Fri Dec 12 " s.values_at 0, -1, 5, 2 # -> ["Fri Dec 12 ", "12", nil, "Dec"] s.scan(/(\w+) (\w+) (\d+) /) # -> nil s.values_at 0, -1, 5, 2 # -> nil