@ and @@

[sas1981]

I have some code below with the @ sign that devides the data set into two datasets; first and second (using the @ sign):

data first second;
INPUT x y @;
OUTPUT first;
INPUT x y;
OUTPUT second;
DATALINES;
1 2 3 4 9 10
5 6 7 8
;
PROC PRINT data=first;
Title 'first';
RUN;
PROC PRINT data=second;
Title 'second';
RUN;

When I replace the @ sign with @@ I am getting the same result but I was assuming I would not. I am wondering why the two different code produce the same output. Thank you for any advise. 

[art297]

You defeat the functionality of @ and @@ by including two input statements. Try the following:

data first_a second_a;
  INPUT x y @;
  if mod(_n_,2) then OUTPUT first_a;
  else OUTPUT second_a;
  DATALINES;
1 2 3 4 5 6
7 8 9 10 11 12
;

data first_b second_b;
  INPUT x y @@;
  if mod(_n_,2) then OUTPUT first_b;
  else OUTPUT second_b;
  DATALINES;
1 2 3 4 5 6
7 8 9 10 11 12
;

Art, CEO, AnalystFinder.com