ruby tricky questions

here’s some tricky questions i got on interviews

difference between Date.today & Date.current

# Returns Time.zone.today when <tt>Time.zone</tt> or <tt>config.time_zone</tt> are     set, otherwise just returns Date.today.
  def current
    ::Time.zone ? ::Time.zone.today : ::Date.today
  end

difference between save & save! save! will raise an error if not successful save will return true or fase

difference between find and find_by find will raise an error find_by will return nil if not founds