ITP - methods - default parameters

When you're defining methods you may want to structure your method so
that it always works, whether given parameters or not. Let's restructure
our say method again so that we can assign a default parameter in case
the caller doesn't send any arguments.

def say(words='hello')
  puts words + '.'
end

say()
say("hi")
say("how are you")
say("I'm fine")

You'll notice that say() prints hello. to the console. We have provided
a default parameter that is used whenever our method is called without
any arguments. Nice!