How to extract group match to array?

Question

I have a string such as:

<?xml version="xyzt" standalone="112.0" sxcx="xcxc"?>

I want to extract the string to array where each element is an attribute of string such as [version="xyzt", standalone="112.0", sxcx="xcxc"].

I tried using string.scan(/\s\w+="\.*"/) do |block| puts block end but I don't get a result.. Please tell me why and how I can do it.

Well, that regex doesn't match anything in that string. Therefore, no output. — Sergio Tulentsev, Jul 27 '16 at 12:39
I am preeeetty sure you don't want to match literal dot zero or more times. Use http://regex101.com, it's great. — Sergio Tulentsev, Jul 27 '16 at 12:40
Please consider using an actual XML parser (e.g. [Nokogiri](http://www.nokogiri.org/)) instead of [parsing XML with regex](https://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/). — Andrew Marshall, Jul 27 '16 at 12:42
Further to @Andrew's point about the output array being invalid, the first element of the array you've shown (`version="xyzt"`) implies that `version` is a local variable produced from the given string. Since Ruby v1.8 it has not been possible to create local variables. The question only makes sense if the first element of the array is the string `'version="xyzt"'`. — Cary Swoveland, Jul 27 '16 at 16:55

Aleksei Matiushkin · Answer 1 · 2016-07-27T12:46:57.067

0

string[/(?<=\<\?xml ).*(?=\?>)/]
#⇒ 'version="xyzt" standalone="112.0" sxcx="xcxc"'

If you need to surround it with square brackets:

?[ << string[/(?<=\<\?xml ).*(?=\?>)/] << ?]
#⇒ '[version="xyzt" standalone="112.0" sxcx="xcxc"]'

To get a hash of attributes:

string[/(?<=\<\?xml ).*(?=\?>)/].split(/\s+/)
                                .map { |e| e.split('=') }
                                .to_h
#⇒ {
#  "standalone" => "\"112.0\"",
#        "sxcx" => "\"xcxc\"",
#     "version" => "\"xyzt\""
# }

edited Jul 27 '16 at 12:46

answered Jul 27 '16 at 12:41

Aleksei Matiushkin

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He wants array of attributes. – Sergio Tulentsev Jul 27 '16 at 12:42
Oh my been a long time since I’ve seen the `?` character string literal used. – Andrew Marshall Jul 27 '16 at 12:52
@AndrewMarshall It saves one keypress per char constant :) – Aleksei Matiushkin Jul 27 '16 at 12:53

score 0 · Answer 2 · answered Jul 27 '16 at 16:50

str = '<?xml version="xyzt" standalone="112.0" sxcx="xcxc"?>'

I assume you want to produce the array:

['version="xyzt"', 'standalone="112.0"', 'sxcx="xcxc"']

You can do that as follows:

arr = str.scan(/[a-z]+\=\S+/)
  #=> ["version=\"xyzt\"", "standalone=\"112.0\"", "sxcx=\"xcxc\"?>"] 

puts arr
# version="xyzt"
# standalone="112.0"
# sxcx="xcxc"?>

How to extract group match to array?

2 Answers2