while and until

while and until

while condition repeats its block as long as the condition is truthy, checked before each iteration. until condition is the inverse, repeating as long as the condition is falsy. Both also support a trailing modifier form for a single statement, like i += 1 while i < 10.

Note: until often reads more naturally than while !condition for conditions phrased as a stopping point.

Example: while and until

count = 1

while count <= 3
  puts "While count: #{count}"
  count += 1
end

count = 1
until count > 3
  puts "Until count: #{count}"
  count += 1
end