Results for: "match"

MatchData#size

Returns the number of elements in the match array.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.length   #=> 5
m.size     #=> 5

MatchData#length

Returns the number of elements in the match array.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.length   #=> 5
m.size     #=> 5

MatchData#offset

Returns a two-element array containing the beginning and ending offsets of the nth match. n can be a string or symbol to reference a named capture.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.offset(0)      #=> [1, 7]
m.offset(4)      #=> [6, 7]

m = /(?<foo>.)(.)(?<bar>.)/.match("hoge")
p m.offset(:foo) #=> [0, 1]
p m.offset(:bar) #=> [2, 3]

MatchData#begin

Returns the offset of the start of the nth element of the match array in the string. n can be a string or symbol to reference a named capture.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.begin(0)       #=> 1
m.begin(2)       #=> 2

m = /(?<foo>.)(.)(?<bar>.)/.match("hoge")
p m.begin(:foo)  #=> 0
p m.begin(:bar)  #=> 2

MatchData#end

Returns the offset of the character immediately following the end of the nth element of the match array in the string. n can be a string or symbol to reference a named capture.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.end(0)         #=> 7
m.end(2)         #=> 3

m = /(?<foo>.)(.)(?<bar>.)/.match("hoge")
p m.end(:foo)    #=> 1
p m.end(:bar)    #=> 3

MatchData#to_a

Returns the array of matches.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.to_a   #=> ["HX1138", "H", "X", "113", "8"]

Because to_a is called when expanding *variable, there’s a useful assignment shortcut for extracting matched fields. This is slightly slower than accessing the fields directly (as an intermediate array is generated).

all,f1,f2,f3 = * /(.)(.)(\d+)(\d)/.match("THX1138.")
all   #=> "HX1138"
f1    #=> "H"
f2    #=> "X"
f3    #=> "113"

MatchData#[]

Match Reference – MatchData acts as an array, and may be accessed using the normal array indexing techniques. mtch[0] is equivalent to the special variable $&, and returns the entire matched string. mtch[1], mtch[2], and so on return the values of the matched backreferences (portions of the pattern between parentheses).

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m          #=> #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8">
m[0]       #=> "HX1138"
m[1, 2]    #=> ["H", "X"]
m[1..3]    #=> ["H", "X", "113"]
m[-3, 2]   #=> ["X", "113"]

m = /(?<foo>a+)b/.match("ccaaab")
m          #=> #<MatchData "aaab" foo:"aaa">
m["foo"]   #=> "aaa"
m[:foo]    #=> "aaa"

MatchData#captures

Returns the array of captures; equivalent to mtch.to_a[1..-1].

f1,f2,f3,f4 = /(.)(.)(\d+)(\d)/.match("THX1138.").captures
f1    #=> "H"
f2    #=> "X"
f3    #=> "113"
f4    #=> "8"

MatchData#named_captures

Returns a Hash using named capture.

A key of the hash is a name of the named captures. A value of the hash is a string of last successful capture of corresponding group.

m = /(?<a>.)(?<b>.)/.match("01")
m.named_captures #=> {"a" => "0", "b" => "1"}

m = /(?<a>.)(?<b>.)?/.match("0")
m.named_captures #=> {"a" => "0", "b" => nil}

m = /(?<a>.)(?<a>.)/.match("01")
m.named_captures #=> {"a" => "1"}

m = /(?<a>x)|(?<a>y)/.match("x")
m.named_captures #=> {"a" => "x"}

MatchData#to_s

Returns the entire matched string.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.to_s   #=> "HX1138"

MatchData#inspect

Returns a printable version of mtch.

puts /.$/.match("foo").inspect
#=> #<MatchData "o">

puts /(.)(.)(.)/.match("foo").inspect
#=> #<MatchData "foo" 1:"f" 2:"o" 3:"o">

puts /(.)(.)?(.)/.match("fo").inspect
#=> #<MatchData "fo" 1:"f" 2:nil 3:"o">

puts /(?<foo>.)(?<bar>.)(?<baz>.)/.match("hoge").inspect
#=> #<MatchData "hog" foo:"h" bar:"o" baz:"g">

MatchData#string

Returns a frozen copy of the string passed in to match.

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