ITP - loops & iterators - until loop

We didn't mention the until loop in the introduction paragraph. We do,
however, need to mention them briefly so that you know about them. The
until loop is simply the opposite of the while loop. You can substitute
it in order to phrase the problem in a different way. Let's look briefly
at how it works.

x = gets.chomp.to_i

until x < 0
  puts x
  x -= 1
end

puts "Done!"

There are instances when using until will allow you to write code that
is more readable and logical. Ruby has many features for making your
code more expressive. The until loop is one of those features.