topic Re: Are they the same thing? in SAS Programming

Are they the same thing?

tianerhu — Thu, 14 Apr 2022 19:26:56 GMT

This chapter gives you the tools to use macro variables
and write simple macros. Macros are particularly useful if you want to make your SAS
programs more flexible and allow them to be used in different situations without having
to rewrite entire programs.( from my textbook of SAS)

macro variables and macros are the same things ?

Re: Are they the same thing?

PaigeMiller — Thu, 14 Apr 2022 19:49:44 GMT

Macros and macro variables are different things.

A macro is a block of SAS code that can be called as needed to execute.

Inside macros (and also outside macros), macro variables are entities that have a value. One way to assign values to macro variables is via the %LET statement. You can change the value of a macro variable as needed, and you can have as many macro variables as needed.

Depending on the values of macro variables used by the macro, the code that is executed will change. In one run of the macro, it does one thing, in another run of the macro, it does a different thing.

A typical (but very simplified) example of a macro named EXTRACT which uses a macro variable called DATE

%macro extract;
     proc sql;
          create table abcd as select * from database.table where date>="&date"d;
     quit;
     title "Data Set ABCD starting at &date";
     proc print data=abcd;
     run;
%mend;

%let date=01MAR2021;
%extract

As you can imagine, if you change the value of DATE, you get a different extract from the database.

Re: Are they the same thing?

Kurt_Bremser — Thu, 14 Apr 2022 19:48:35 GMT

@tianerhu wrote:

macro variables and macros are the same things ?

No. Start here: Getting Started with the Macro Facility

then Replacing Text Strings Using Macro Variables

then Generating SAS Code Using Macros

Re: Are they the same thing?

tianerhu — Thu, 14 Apr 2022 19:50:47 GMT

Thank you for your help.