A SAS 9.3 Macro Trick: %put &=var

This is new since SAS 9.3 on how to display macro variable name and its value. Try to run

%let var=1,2,3;
%put &=var;

or

%macro test(var);
    %put &=var;
%mend;
%test(%str(1,2,3))

and you will get in Log window

VAR=1,2,3

You can read from SAS 9.3 online doc:

If you place an equal sign between the ampersand and the macro variable name of a direct macro variable reference, the macro variable’s name displays in the log along with the macro variable’s value.

In SAS 9.2 and prior, you should type the macro variable twice:

%let var=1,2,3;
%put var=&var;

PS: it is called a “Tip” in SAS 9.3 online doc, but I’d rather call it a trick: not critical but nice to have (save your typing!). You may be also interested in Rick Wicklin’s differentiation on Tip and Technique.