CODEWITHSUNDEEP
rubyinstance-variables
Tom
Tom

Reputation: 460

My instance variable isn't holding its value

Okay, so I'm building something that takes a text file and breaks it up into multiple sections that are further divided into entries, and then puts <a> tags around part of each entry. I have an instance variable, @section_name, that I need to use in making the link. The problem is, @section_name seems to lose its value if I look at it wrong. Some code:

def find_entries
  @sections.each do |section|
    @entries = section.to_s.shatter(/(some) RegEx/)
    @section_name = $1.to_s
    puts @section_name
    add_links
  end
end

def add_links
  puts "looking for #{@section_name} in #{@section_hash}"
  section_link = @section_hash.fetch(@section_name)
end

If I comment out the call to add_links, it spits out the names of all the sections, but if I include it, I just get:

looking for  in {"contents" => "of", "the" => "hash"}

Any help is much appreciated!

Upvotes: 1

Views: 70

Answers (1)

Arup Rakshit
Arup Rakshit

Reputation: 118261

$1 is a global variable which can be used in later code.$n contains the n-th (...) capture of the last match

"foobar".sub(/foo(.*)/, '\1\1')
 puts "The matching word was #{$1}" #=> The matching word was bar

"123 456 789" =~ /(\d\d)(\d)/
 p [$1, $2] #=> ["12", "3"]

So I think @entries = section.to_s.shatter(/(some) RegEx/) line is not doing match properly. thus your first matched group contains nothing. so $1 prints nil.

Upvotes: 1

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