class ActionController::Parameters

params.extract_value(:tags) # => ["ruby", "rails", "", "web"]
params = ActionController::Parameters.new(tags: "ruby,rails,,web")

the returned array will include empty strings.
Note that if the given +key+'s value contains blank elements, then

params.extract_value(:non_existent_key) # => nil
params.extract_value(:tags, delimiter: ",") # => ["ruby", "rails"]
params.extract_value(:id) # => ["1", "123"]
params = ActionController::Parameters.new(id: "1_123", tags: "ruby,rails")

Returns parameter value for the given +key+ separated by +delimiter+.

def extract_value(key, delimiter: "_")
  @parameters[key]&.split(delimiter, -1)
end