sas - do loop within data step with unresolve varialbes -

i have several parameters proc sql select into: , store of them dataset named parm. following code attempted:

i got following parameter previous step:

%let count = 4; %let yymm1 = '1505'; %let yymm2 = '1504'; %let yymm3 = '1503'; %let yymm4 = '1502'; 

here data step:

data parm;     format yymm1 - yymm&count. $4.;     array a(*) yymm1-yymm&count.;     = 1 &count.;         a(i) = "&&yymm&i";     end; run; 

problem &i , &&yymm cannot resolved.

while echo @joe 's comment, here suggestions on given situation. first make sure if macro variable values contain single quotes or not. have in macro variable definition, while length=4 in data step won't cut you. @joe suggested, need separate macro variable , data step variable doing following:

%let count = 4; %let yymm1 = '1505'; %let yymm2 = '1504'; %let yymm3 = '1503'; %let yymm4 = '1502';  data parm;     format yymm1 - yymm&count. $6.;     array a(*) yymm1-yymm&count.;      = 1 &count.;         a(i) = symget(cats('yymm',i));     end; run;