SAS Macro Language Magic

Chapter 2: Shifting Gears: Macro Language

As the focus shifts from the SAS language to the macro language, similar principles apply. It pays to expand your knowledge, to experiment, and to keep up with the latest software features, all the while attempting to keep programs as simple as possible. For example, just as the SCAN function can read a list from right to left, the %SCAN function can as well. Revisit this macro parameter from the beginning of Chapter 1:

by_varlist = state county town,

Based on that parameter, a macro must generate this code (with the bold sections based on &BY_VARLIST):

proc sort data=municipalities;

     by state county town;

run;

data last_one;

     set municipalities;

     by state county town;

     if last.town;