Only when working with explicit Booleans, yes. Otherwise no: [21] pry(main)> foo = 1 => 1 [22] pry(main)> bar = false => false [23] pry(mai

Only when working with explicit Booleans, yes. Otherwise no: [21] pry(main)> foo = 1 => 1 [22] pry(main)> bar = false => false [23] pry(main)> foo && !bar => true [24] pry(main)> foo &! bar TypeError: can't convert true into Integer from (pry):24:in `&' In this case, the behavior is inappropriate in that Ruby evaluates only false and nil for False, and everything else as True. I'm going to assume this is some quirk or "feature" as part of the bitwise operator '&'.