topic Re: Difference between &A and &A. in SAS Programming

Difference between &A and &A.

astha8882000 — Tue, 24 Apr 2018 21:14:07 GMT

I'm looking at a piece of code given below, this is just a small part of a really big project. But I'm unable to understand a concept here:

Proc sql noprint;

Select max(count) into:A

From ABC;

quit;

DATA _NULL_;

IF &A. < 1 THEN

DO;

[some code]

END;

Here, A is a macro variable as provided in the proc sql statements, then instead of referencing it as &A in the data step, why is this being referred to as &A.. Why is there a period added while referencing it?

Re: Difference between &A and &A.

novinosrin — Tue, 24 Apr 2018 21:18:35 GMT

Why is there a period added while referencing it?

Test the same code without the period as suffix

Re: Difference between &A and &A.

Astounding — Tue, 24 Apr 2018 21:29:23 GMT

The period is optional when referring to a macro variable. It doesn't matter if you use it here or not.

It comes in handy when the name of the macro variable is ambiguous. For example:

&ABC

Is this the macro variable &A followed by the letters "BC" or is it the macro variable &ABC? For the macro variable &A followed by the letters "BC" you would clarify that by using:

&A.BC

Re: Difference between &A and &A.

astha8882000 — Tue, 24 Apr 2018 21:39:13 GMT

ABC is a table and A is just a variable that is obtaining some value from that table.

Re: Difference between &A and &A.

Astounding — Tue, 24 Apr 2018 21:44:10 GMT

OK, I think you need a few examples to clarify then. Try running this code:

%let a=1;

%let ab=2;

%let abc=3;

%put abc;

%put &abc;

%put &abc.;

%put &a.bc;

%put &ab.c;