A macro variable can be 64K characters long. So you could easily have thousands of variables. ... View more

Those two programs are not equivalent.  The second one does NOT run the %INNER macro. There is only a small performance penalty for re-compiling a macro since it does not involve any actual data manipulation. The bigger penalty will be paid in maintaining the program source file and in confusion that the nested structure will instill into novice users that might assume there was a valid reason for nesting the macro definitions.   Method 1 FIXED %macro inner; %mend; %macro outer;     %inner; %mend;   Method 2 FIXED %macro inner; %mend; %macro outer; %mend;   ... View more

@Tom : Thank you very much for your detailed explanation. Really, it is a wonderful solution. That's very kind from you. Please, I want to understand some thing in your solution about the new  variable  __name in one hand, and by the instruction length __name $200 ;  We will create a new variable __name is initialzed to blank( =' ')   On the other hand, by the instruction if _n_>0 then __name = quote(strip(vvaluex(__name))); We will get  this results Name;Sex;Age; "Alfred";"M";"14"; So, please, how can this new variable __name is initialized to "blank" and gives the réésult is not blank ? Is there a new initialion for the new variable __name by the instruction ?   call vnext(__name); in the first time, the variable __name became Name, in the second time Sex, in the third time  Age    ?   At the end thank you again for your answers.     ... View more

It means try to write your the desired macro. If you need further help, post what you've tried and identify where you're having issues.      ... View more