**StudySAS Blog: Mastering Clinical Data Management with SAS**

Mastering Global and Local Macro Variables in SAS: A Detailed Guide for SDTM Programmers Mastering Global and Local Macro Variables in SAS: A Detailed Guide for SDTM Programmers In SAS programming, especially when dealing with complex tasks such as SDTM (Study Data Tabulation Model) dataset creation, macro variables play a critical role in automating processes and managing large amounts of data efficiently. Understanding the distinction between Global and Local macro variables, and how to use them appropriately, is essential for writing clean, maintainable, and robust code. What are Macro Variables in SAS? Macro variables in SAS are placeholders that store text strings, which can be reused throughout your SAS programs. They are part of the SAS Macro Language and are used to make your code more dynamic and flexible. By using macro variables, you can avoid hardcoding values and make your code easier to modify and scale. There are two pri...

Here are the 2 important questions always comes up in our minds ,(& vs && vs &&& and single dot and double dots ) when we are dealing with macros for the first time and here are the answers for them. I did find a very good regarding the above topics in the one of the SAS forums and IAN WHITLOCK explained it very clear. direct link : or when to use &,&&,and &&&,how do we distinguish? &MACVAR references a macro variable. The rule is that the scanner reads from left to right. Two ampersands resolve to one and scanner continues. If the resulting expression has ampersands then that expression is scanned again. So &&x resolves to &x resolves to value of X &&&x resolves to & followed by the value of X which then resolves to the value of the variable indicated. If you are familiar with TSO CLISTS (even if you are not), they are very similar to SAS macro. SAS was originally based on PL1, so both SAS syntax an...