topic Re: explanation in SAS Programming

explanation

helloSAS — Mon, 21 Oct 2013 17:19:52 GMT

Hi, I came across a wierd situation. Can someone explain me this?

One of our prod jobs is using %let statement as below and it works

%let rundt = today();

however, when i run the same &rundt resolves to today() and not actual date of today.

I've to use %let rundt = %sysfunc(today());

why is it that it works without %sysfunc in other jobs?

Re: explanation

Astounding — Mon, 21 Oct 2013 17:36:57 GMT

The statements do the same thing, whether it is in your job or in a production job. Whenever you see this statement:

%let rundt = today();

the value of &RUNDT is not a number, but is the 7 characters "today()".

What you are not observing is how the production program uses &RUNDT. For example, it may use this statement in a DATA step:

date = &RUNDT;

In that case, the statement resolves into:

date = today();

When that statement appears in a DATA step, it executes and DATE receives the proper numeric value.

Re: explanation

helloSAS — Mon, 21 Oct 2013 18:17:17 GMT

Thank you!

One more question

Why am i not able to use below statement?

%let month1x = %sysfunc(month(today()));

where as, I'm able to use

data _null_ ;

call symput('month1x',month(today()));

run;

Re: explanation

Astounding — Mon, 21 Oct 2013 19:13:48 GMT

You'll need to use %SYSFUNC for each function ... once for MONTH and once for TODAY. I hope I get the number of parentheses correct:

%let month1x = %sysfunc(month(%sysfunc(today())));

Re: explanation

helloSAS — Mon, 21 Oct 2013 19:56:42 GMT

Thank you!

I was able to get same results using both ways below. However, I had to use ' ' quotes around month in intnx function for call symput and not for %sysfunc.

Can you tell me the reason why?

%let month2 = %sysfunc(month(%sysfunc(intnx(month,%sysfunc(today()),-1))));
%put &month2;

data _null_;
call symput ('month1',month(intnx('month',today(),-1)));
run;
%put &month1;

Re: explanation

Astounding — Mon, 21 Oct 2013 20:01:07 GMT

Except in rare cases where a number is required, macro language assumes all strings are text. Easy examples:

%let name=Fred;

%let name="Fred";

The first statement assigns &NAME a 4-character value. The second assigns &NAME a 6-character value. The quotes are not needed to identify a string, and so become part of the value assigned to &NAME.

You're looking at the same principle, but in a more complex setting.