? is Ruby shorthand for referencing a character.
irb(main):020:0> ?a => 97 irb(main):021:0> ?a == "a"[0] => true irb(main):014:0> ?? => 63 irb(main):015:0> !?? => false irb(main):016:0> !!?? => true
Since ?? equals 63, it is equivalent to true in a boolean test. That means we can negate it with a bang!
Categories: ruby