topic Re: The semicolon after calling a macro, is it better to omit it? in New SAS User

The semicolon after calling a macro, is it better to omit it?

cosmid — Sun, 17 Dec 2023 21:29:16 GMT

Hi,

The book SAS Certified Professional Guide has this caution:

A semicolon after a macro call might insert an inappropriate semicolon into the resulting program, leading to errors during compilation or execution.

After searching the internet, it seems a lot SAS users think the extra semicolon will not be an issue. Anyone has an example of when the semicolon after a macro call will be an issue?

Thanks

Re: The semicolon after calling a macro, is it better to omit it?

PaigeMiller — Sun, 17 Dec 2023 22:24:37 GMT

@cosmid wrote:

The book SAS Certified Professional Guide has this caution:

A semicolon after a macro call might insert an inappropriate semicolon into the resulting program, leading to errors during compilation or execution.

Agree completely, there are situations where a semi-colon after calling a macro is not a problem, and situations where it is a problem. Best to leave it off, and then you never run into a problem with an extra semi-colon in your code.

Re: The semicolon after calling a macro, is it better to omit it?

Patrick — Sun, 17 Dec 2023 22:23:51 GMT

I've got into error conditions when calling a macro without parameters not using a semicolon.

%macro test;
  <some code>
%mend;
%test

This is why I always define and call macros like below even if they don't have a parameter.

%macro test();
  <some code>
%mend;
%test()

I personally prefer to end macros with a semicolon even though it's not necessary - except if it's a function style macro used in the middle of some expression where a semicolon of course would terminate the SAS expression in the wrong place. ...but then I avoid such function style macros as far as I can.

Can't think of any other case where this unnecessary semicolon would create issues.

Re: The semicolon after calling a macro, is it better to omit it?

Tom — Mon, 18 Dec 2023 00:44:50 GMT

It is more likely an issue in the reverse situation. You are calling a macro that has defined parameters, but you don't need to pass any parameter values in the call. In that case SAS will wait until it sees the semi-colon to know that the macro call is done.

7    %macro noparms;
8    * This macro does not use parameters;
9    %mend noparms;
10
11   options mprint;
12   %noparms
MPRINT(NOPARMS):   * This macro does not use parameters;

13   %macro parms(x=1);
14   * This macro does use parameters;
15   %mend parms;
16
17   options mprint;
18   %parms

If you know the macro you are calling is going to generate one or more complete statements then adding a semi-colon does no harm and could fix the problem above when running interactively.