How to match all occurrences of a regex
You can use string.scan(your_regex).flatten
. If your regex contains groups, it will return in a single plain array.
string = "A 54mpl3 string w1th 7 numbers scatter3r ar0und"
your_regex = /(\d+)[m-t]/
string.scan(your_regex).flatten
=> ["54", "1", "3"]
Regex can be a named group as well.
string = 'group_photo.jpg'
regex = /\A(?<name>.*)\.(?<ext>.*)\z/
string.scan(regex).flatten
You can also use gsub
, it's just one more way if you want MatchData.
str.gsub(/\d/).map{ Regexp.last_match }
To find all the matching strings, use String's scan
method.
str = "A 54mpl3 string w1th 7 numb3rs scatter36 ar0und"
str.scan(/\d+/)
#=> ["54", "3", "1", "7", "3", "36", "0"]
If you want, MatchData
, which is the type of the object returned by the Regexp match
method, use:
str.to_enum(:scan, /\d+/).map { Regexp.last_match }
#=> [#<MatchData "54">, #<MatchData "3">, #<MatchData "1">, #<MatchData "7">, #<MatchData "3">, #<MatchData "36">, #<MatchData "0">]
The benefit of using MatchData
is that you can use methods like offset
:
match_datas = str.to_enum(:scan, /\d+/).map { Regexp.last_match }
match_datas[0].offset(0)
#=> [2, 4]
match_datas[1].offset(0)
#=> [7, 8]
See these questions if you'd like to know more:
- "How do I get the match data for all occurrences of a Ruby regular expression in a string?"
- "Ruby regular expression matching enumerator with named capture support"
- "How to find out the starting point for each match in ruby"
Reading about special variables $&
, $'
, $1
, $2
in Ruby will be helpful too.
if you have a regexp with groups:
str="A 54mpl3 string w1th 7 numbers scatter3r ar0und"
re=/(\d+)[m-t]/
you can use String's scan
method to find matching groups:
str.scan re
#> [["54"], ["1"], ["3"]]
To find the matching pattern:
str.to_enum(:scan,re).map {$&}
#> ["54m", "1t", "3r"]
Using scan
should do the trick:
string.scan(/regex/)