Repeat a process for multiple prefixes

[duckieduck]

Hi! I'm repeating the same process for 13 prefixed and am wondering if it could be done with array methods. Here is the code I tried but got an error message:

data data_wide;
set data_array;
array prefix{13} pa pb pc pd pe pf pg ph pi pj pk pl pm;
do n = 1 to 13;
	if prefix{n}_15 = . or prefix{n}_45 = . then do;
		prefix{n}_15 = .;
		prefix{n}_45 = .; 
	end;
end;
run;

ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *,
              **, +, -, /, ;, <, <=, <>, =, >, ><, >=, AND, EQ, GE, GT, IN,
              LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, ^=, |, ||, ~=.

I don't want to revert back to just copy-and-pasting the same code 13 times but how could I make the process more efficient and neat? Would appreciate any help. Thank you!

[mkeintz]

I believe you are effectively trying to do this:

 	if pa_15 = . or pa_45 = . then do;
		pa_15 = .;
		pa_45 = .; 
	end;

followed by the same for pb_15,pb_45  through pm_15,pm_45.  Two suggestions :

First, don't make a do group.  Instead use code like this:

  if n(pa_15,pa_45)=1 then call missing(pa_15,pa_45);

followed by pb through pm.

Second, to use arrays, use this structure:

  array p15 {13}  pa_15 pb_15 pc_15 pd_15 pe_15 pf_15 pg_15 
                  ph_15 pi_15 pj_15 pk_15 pl_15 pm_15;

  array p45 {13}  pa_45 pb_45 pc_45 pd_45 pe_45 pf_45 pg_45 
                  ph_45 pi_45 pj_45 pk_45 pl_45 pm_45;

  do 1 to 13;
    if n(p15{n},p45{n})=1 then call missing(p15{n},p45{n});
  end;

To do it the way you originally conceived, you would have to use sas macro coding, which does not seem to be well-justified, given the relatively simple technique I'm suggesting.