topic Re: Concatenating iteratively in a macro in New SAS User

Concatenating iteratively in a macro

tonoplast — Tue, 28 May 2019 02:45:16 GMT

Hello everyone,

I am trying to solve this problem but I haven't been able to. Please help.

%let thisvar = BUS;

%let buslist = A B C D E;

%macro A;

%do k = 1 %to %sysfunc(countw(&buslist));

%let list = %scan(&bustlist, &k)

%let xlist = %sysfunc(cats(&list,1_,&thisvar));

** I don't know how to do this part ***

%end;

%mend;

%A;

What I would like to have in the end is:

A1_BUS B1_BUS C1_BUS D1_BUS E1_BUS into some macro variable (say %let BUS=);

Please help. Thank you!

Re: Concatenating iteratively in a macro

tonoplast — Tue, 28 May 2019 03:13:09 GMT

Looks like I figured it out. If there is an easier way / better way than this, please let me know (this probably needs re-work from the beginning). Thank you.

%let thisvar = BUS;

%let buslist = A B C D E;

%let finlist=;

%macro A;

%do k = 1 %to %sysfunc(countw(&buslist));

%let list = %scan(&bustlist, &k)

%let xlist = %sysfunc(cats(&list,1_,&thisvar));

%let finlist = %sysfunc(cats(&finlist. &xlist));

%end;

%mend;

%A;

%put &finlist;

Re: Concatenating iteratively in a macro

heffo — Tue, 28 May 2019 03:50:53 GMT

Some typos in the original question! But tonoplasts code works exactly as it should.

%let thisvar = BUS;
%let buslist = A B C D E;
%let finlist=;

%macro A;
	%do k = 1 %to %sysfunc(countw(&buslist));
		%let list = %scan(&buslist, &k);
		%let xlist = %sysfunc(cats(&list,1_,&thisvar));
		%let finlist = %sysfunc(cats(&finlist. &xlist));
	%end;
%mend;
%A;

%put &finlist;

Re: Concatenating iteratively in a macro

FreelanceReinh — Tue, 28 May 2019 09:31:29 GMT

Hello @tonoplast,

Usually, SAS functions such as CATS are not needed to concatenate text in macro language. You could simplify the %DO loop to

%do k = 1 %to %sysfunc(countw(&buslist));
  %let finlist = &finlist %scan(&buslist, &k)1_&thisvar;
%end;

Edit: Further simplified as per @Astounding's reminder.

Re: Concatenating iteratively in a macro

Astounding — Tue, 28 May 2019 08:58:50 GMT

One more small simplification: remove the %LEFT function. The %LET statement will automatically ignore leading blanks.

Re: Concatenating iteratively in a macro

FreelanceReinh — Tue, 28 May 2019 09:34:41 GMT

Oh yes, of course! Thanks for reminding me. (This was the result of too quickly switching from a version using a trailing blank.)

Re: Concatenating iteratively in a macro

tonoplast — Thu, 30 May 2019 01:25:15 GMT

Thank you, everyone!!