Macro %then semicolon

As a creature of habit, I typically write %IF %THEN/%ELSE statements using %DO blocks. However, is a %DO block needed for a one line statement? This blog post answers that question via a series of test conditions. Please understand that this is a very simple example program to illustrate the problem that was experienced.

Test 1 single semicolons

%macro test();
   data mydsn;
      %if &sysver = 9.4 %then x = 1;
      %else x = 0;
      date = date();
   run;
%mend;
%test();

80 date = date();   run;
                    ____
                    22
 
ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *, **, +, -, /, ;, <, <=, <>, =, >, ><, >=, AND, EQ, GE, GT, IN, LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, ^=, |, ||, ~=.  

That seems odd, but I guess I need to add another semicolon to each of the %IF and %ELSE lines to terminate the macro language statements. Here are the results of that attempt.

Test 2 - using two semicolons

 73         %macro test();
 74            data mydsn;
 75               %if &sysver = 9.4 %then x = 1;;  /* notice use of two semicolons */
 76               %else x = 0;;                    /* notice use of two semicolons */
ERROR: There is no matching %IF statement for the %ELSE.
ERROR: A dummy macro will be compiled.
 77               date = date();
 78            run;
 79         %mend;
 80         %test();

Test 3 - two semicolons on the %ELSE line

%macro test();
   data mydsn;
      %if &sysver = 9.4 %then x = 1;  /* one semicolon here */
      %else x = 0;;                   /* two semicolons here */
      date = date();
   run;
%mend;
%test();

NOTE: The data set WORK.MYDSN has 1 observations and 2 variables.

While the use of one semicolon on the first line and two on the second macro language line works, I find it confusing. In the name of ease of reading and maintaining, I still prefer the use of %DO blocks.

Test 4 - %DO blocks

%macro test();
   data mydsn;
      %if &sysver = 9.4 %then %do;
       x = 1;
      %end;
      %else %do;
       x = 0;
      %end;
      date = date();
   run;
%mend;
%test();

NOTE: The data set WORK.MYDSN has 1 observations and 2 variables.