Search code examples
sassas-macro

Why does the put and let statements need to be prefixed by a % sign in SAS

In SAS, why cannot we write 

let name = abc;
put "&name";

Why do we have to include the % sign like this:

%let name = abc;
%put &name;

Imagine I am writing the statements in the main body of the code, not inside a data step.

Also, is the second way of writing it same as:

%macro test;
%let name = abc;
%put &name; 
%mend;
Solution

  • %let and %put are part of the SAS macro language. Macro language statements are (with one or two particular exceptions) prefixed by % to tell the SAS macro parser to operate on them.

    They do entirely different things from the non-% version - except when it works out to the same thing. You can write put "&mvar."; - as long as it's in a data step (As that's a data step statement). Macro commands/functions/statements are allowed in open code sometimes (and not in others).

    Writing it inside an actual macro is more-or-less the same. There are scoping issues, though; &name won't be available outside of that macro, unless it's been declared global.