topic Is there a way to loop through a series of like parameters? in SAS Programming

Is there a way to loop through a series of like parameters?

DavidPhillips2 — Thu, 15 Feb 2018 22:04:47 GMT

%macro combineYears(Year1, Year2, Year3, Year4, Year5);

do year1 to year5;

/*process logic*/

end;
%end;

Re: Is there a way to loop through a series of like parameters?

Astounding — Thu, 15 Feb 2018 22:14:55 GMT

Yes, but it would be easier if you get rid of the commas between the values. Here's some documentation:

https://blogs.sas.com/content/sastraining/2015/01/30/sas-authors-tip-getting-the-macro-language-to-perform-a-do-loop-over-a-list-of-values/

Re: Is there a way to loop through a series of like parameters?

Reeza — Thu, 15 Feb 2018 22:24:59 GMT

Depends on how you want to use it. You may end up finding that a %DO loop may work just as well.

You can also check out examples 3 and 4 here:

https://communities.sas.com/t5/SAS-Communities-Library/SAS-9-4-Macro-Language-Reference-Has-a-New-Appendix/ta-p/291716

Re: Is there a way to loop through a series of like parameters?

Satish_Parida — Fri, 16 Feb 2018 09:45:16 GMT

It can be done as follows.

%macro combineYears(Year1, Year2, Year3, Year4, Year5);
%do i=1 %to 5;
	%put year= &&year&i;
	/*process logic*/
%end;
%mend combineYears;

%combineYears(2000, 2001, 2010, 2015, 2018);


*LOG

year= 2000
year= 2001
year= 2010
year= 2015
year= 2018

It will be good if you also pass the number of years you are passing and use to loop control.

Please let us know if it helped.

Re: Is there a way to loop through a series of like parameters?

ballardw — Fri, 16 Feb 2018 20:43:31 GMT

@Satish_Parida your approach, while it will work would have issues if the user only wants to process 2 years and would require a diffent macro to process any different number of year.

This is what @Astounding meant by getting rid of commas:

%macro combineYears(YearList);
%do i=1 %to %sysfunc(countw(&yearlist));
	%put year= %scan(&yearlist,&i);
  
	/*process logic*/
%end;
%mend combineYears;

%combineYears(2000 2001 2010 2015 2018);

which will process any explicit list of one or more items. Note that we have no check for and empty list though nothing inside the %do loop will happen so likely okay for that, or checks to ensure that the values in the list are valid for any other purpose.