Clean way to return an array from X.times in Ruby

Question

I often want to perform an action on an array X times then return a result other than that number. The code I usually write is the following:

  def other_participants
    output =[]
    NUMBER_COMPARED.times do
      output << Participant.new(all_friends.shuffle.pop, self)
    end
    output
  end

Is there a cleaner way to do this?

Answer 1

sounds like you could use map/collect (they are synonyms on Enumerable). it returns an array with the contents being the return of each iteration through the map/collect.

def other_participants
  NUMBER_COMPARED.times.collect do
    Participant.new(all_friends.shuffle.pop, self)
  end
end

You don't need another variable or an explicit return statement.

http://www.ruby-doc.org/core/Enumerable.html#method-i-collect

Answer 2

You could use each_with_object:

def other_participants
  NUMBER_COMPARED.times.each_with_object([]) do |i, output|
    output << Participant.new(all_friends.shuffle.pop, self)
  end
end

From the fine manual:

each_with_object(obj) {|(*args), memo_obj| ... } → obj
each_with_object(obj) → an_enumerator

Iterates the given block for each element with an arbitrary object given, and returns the initially given object.
If no block is given, returns an enumerator.

Answer 3

I thing something like this is best

def other_participants
  shuffled_friends = all_friends.shuffle
  Array.new(NUMBER_COMPARED) { Participant.new(shuffled_friends.pop, self) }
end