set -- 1 2 3 4 5 6 7 8 9 10 11 12 13
[ "$#" = 13 ] || echo '$# wrong'
[ "${#}" = 13 ] || echo '${#} wrong'
[ "${##}" = 2 ] || echo '${##} wrong'
set --
[ "$#" = 0 ] || echo '$# wrong'
[ "${#}" = 0 ] || echo '${#} wrong'
[ "${##}" = 1 ] || echo '${##} wrong'