How to determine 'even' and 'odd' observations in a dataset

Well ,lets create a ds ‘two’ having only even numbered obs from ds ‘one’ .

/* create sample data set */
data one;
do i=1 to 10;
output;
end;
run;


data two;
set one;
if mod(i,2)=0 then output;/*outputs only even obs*/
run;

proc print;
run;

/* RESULTS */
Obs i
1 2
2 4
3 6
4 8
5 10