flip_flop_operator

🔄 Control Flow with Flip-Flop Operator

Ruby’s flip-flop (expr1..expr2) operator provides stateful conditionals: it turns true when expr1 is true and turns false when expr2 becomes true. This is handy for range-based filtering in loops.

lines = (1..10).to_a
selected = []
lines.each do |n|
  if (n == 3..n == 6)
    selected << n
  end
end
puts selected.inspect
# => [3, 4, 5, 6]