The 'Until' Loop

The complement to the while loop is the until loop. It's sort of like a backward while:

i = 0
until i == 6
  i = i + 1
end
puts i

1. In the example above, we first create a variable i and set it to 0 (zero).
2. Then we execute a block of code until i is equal to 6. That block of code increments i.
3. When i is equal to 6, the block ends.
4. Finally, we print 6, the value of i, to the console.