I think I got it now.
If i provide scriptname -s schema -u user -d database, $# evaluates to 6 based on no of options and its values. (-s schema) 2, (-u user) 2 and (d database ) 2.

So if it is -d database -f it evaluates to 3 (-d database)2 and (-f) 1.
If he specifies -d database and -t ( That too evaluates to 3) .

How do i check if he has specified -t or -f then ?