I am currently studying for my Advanced SAS certification using Chapter 16 of the Advanced Prep Guide.  On page 586 is SAS code for using nested do-loops to load an 2-dimensional array ("Targets") from a SAS dataset (sasuser.ctargets) which contains stored array data.  The beginning of the code reads as follows: data work.lookup;   array Target{1997:1999, 12} _temporary_;   if _n_=1 then do i = 1 to 3;      set sasuser.ctargets;      array mnth(*) Jan--Dec;      do j=1 to dim(mnth);         targets(year,j) = mnth(j);      end;   end; [more code ... that transfers the data from the targets array to the data set work.lookup] My question concerns where the data from sasuser.ctargets lives when it is "set," and how the 3 iterations of the outer do-loop moves down the data coming from sasuser.ctargets to transfer it into the arrany mnth. I read the "set sasuser.ctargets" statement as reading the data from sasuser.ctargets into the data set work.lookup -- but work.lookup is eventually used to build the new data set that only contains data from sasuser.ctargets in a sort of a transposed format.  I also do not see where "year" gets defined -- it just appears when needed to indicate the row number.  Since year is not defined, and since year does not = i, how does the outer do loop know to iterate down the rows?     sas   ... View more