sas - Resolving macro variables in hash declaration? -

running bit unusual. feel silly error on part, life of me can't figure out be.

the following works fine:

declare hash hash&foo1.&foo2.&foo3.&foo4.(); ... 

the following not work:

declare hash hash%do bar = 1 %to &nvars.;&&foo&bar..%end;(); ... 

they both appear resolve

declare hash hash1111(); 

but latter throws syntax error. thoughts? specific error is:

line generated macro variable "foo1". 1 error 22-322: syntax error, expecting 1 of following: name, (, ;. ... declare hash hash1111(); note: line generated macro variable "foo4". hash1111 

if want generate code fragments, before use fragment.
following code illustration:

%macro test; %global foobar; %let foobar = ; %let foo1 = 1; %let foo2 = 1; %let foo3 = 1; %let foo4 = 1;  %let foobar = &foo1.; %do bar = 2 %to 4;   %let foobar = %sysfunc(cats(&foobar., &&foo&bar..));   %put *&foobar.*; %end; %mend; %test; 

now kann use macrovariable foobar wherever like. e.g.

declare hash hash&foobar.();   

aftersome research found solution in http://www2.sas.com/proceedings/sugi28/011-28.pdf

you need unquote macro loop. don't know why, following code working:

%macro test3();     %global foobar;     %let foobar =;     %let foo1 = 1;     %let foo2 = 1;   %let foo3 = 1;   %let foo4 = 1;    data test2;     declare hash hash%unquote(%do bar = 1 %to 4;&&foo&bar..%end;)();   run; %mend;   %test3; 

the following statement of sugi-paper lead solution: "in case, older documentation gave simple rule:
if mprint looks , sas compiler not understand it, try %unquote."