SAS : definition of variables in if loop - sas

Question

I am new to SAS macro writing and I have been struggling with writing a code for the following instance.
%let DateOfInterest= "15jul2016"d;
%let yearyyyy=%sysfunc(putn(&DateOfInterest,year4.));
%let yearyyyy2=eval(yearyyyy+1);
data _null_;
if "01JAN2016"d<=&DateOfInterest<="31MAR2016"d then do;
%let reportdate="31MAR2016"d;
%let reportdate2="01APR2016"d;
%let reportdate3="01JAN2016"d;
%let QuarterOfInterest=Q1;
if "31MAR2016"d<&DateOfInterest<="30JUN2016"d then do;
%let reportdate="30JUN2016"d;
%let reportdate2="01JUL2016"d;
%let reportdate3="01APR2016"d;
%let QuarterOfInterest=Q2;
if "30JUN2016"d<&DateOfInterest<="30SEP2016"d then do;
%let reportdate="30SEP2016"d;
%let reportdate2="01OCT2016"d;
%let reportdate3="01JUL2016"d;
%let QuarterOfInterest=Q3;
if "30SEP2016"d<&DateOfInterest<="31DEC2016"d then do;
%let reportdate="31DEC2016"d;
%let reportdate2="01JAN2017"d;
%let reportdate3="01OCT2016"d;
%let QuarterOfInterest=Q4;
end;
end;
end;
end;
run;
The code runs without any problem. However, whatever DateOfInterest I choose, the reportdate variables come out to be the ones specified in the last if loop. is there a way to change the code in order to have reportdates variable in line with the DateOfInterest?
Thanks.

Answer 1

You're combining macro with data step in a way that doesn't work. Macro language and data step language are basically unrelated: macro language can write data step code, and the other way around, but not affect each other generally.
In particular, macro code is compiled and executed first, before any dataset is opened or any data step code is compiled or executed. That's the point really - it lets you write datastep code pre-compilation.
So
if ... then do;
%let something
end;
That doesn't work, because the macro %let happens first, then later the data step happens.
%if ... %then %do;
%let something
%end;
That works, because it's all in the macro language. Generally speaking, if it doesn't have a % at the start, it's not a macro statement/function, and won't work on the macro language.
What you're doing is going to have some more complications, though. You have to be in a macro to use %if, but you also have scoping issues.
So a general small macro like this would be:
%let mval=1;
%macro set_things;
%if &mval=1 %then %do;
%let mval1=1;
%end;
%else %if &mval=2 %then %do;
%let mval2=1;
%end;
%else %do;
%let mval0=1;
%end;
%mend;
%set_things();
%put &=mval &=mval0 &=mval1 &=mval2;
Notice that doesn't work: because it's not global, so you need one more line inside the macro:
%global mval0 mval1 mval2;
That tells SAS to make them available in the global area.