Macro variable from other macro variable

Question

Let say I want to create a macro variable like:

%let year=2019;

%let ye = SUBSTR(%year,3,2) (I want to extract 19 from 2019).

But it does not work. Do we have any of creating such a macro variable like this?

Update: My code in fact is like

%let yearend = 2019
% let monthend = 04

And now I want to create a macro variable like "data1904" in order to use the dataset named "data1904" in my library. So what I want to create is something like

%let dataname= CAT(SUBSTR(%yearend,3,2),%monthend)

Answer 1

You use & to reference a macro variable, not %. When you use a function in macro code you need to wrap it in %SYSFUNC() so the compiler can differentiate between text and code.

%let ye = %sysfunc(substr(&year, 3, 2));

Or alternatively there is the %SUBSTR() macro function which allows you to skip the %SYSFUNC().

%let ye = %substr(&year, 3, 2);