From: Jens Wille <jens.wille@...>
Date: 2011-10-15T00:31:30+09:00
Subject: Re: What’s the best way of checking if an argument has been given or not?

luke gruber [2011-10-14 17:15]:
> That way, the instance won't be available across classes and you
> can just check if the argument responds_to :missing?
or you can just do this:

class A

  def b(c = d = true)  # or some other truthy value
    if d
      puts 'no argument was given'
    else
      puts c
    end
  end

end

can't remember where i first saw it, but it works perfectly ;)

cheers
jens