check if variables with different suffix are one on one

[laiguanyu001]

Hello,

I am a beginner at SAS.

I have a data set with variable names look like this. aflag1 aflag2 bflag1 bflag2 cflag1 cflag2 

I want to find data where  *flag1 value is missing and *flag2 is not missing. 

For example if a line in data is aflag1 = '' and aflag2 <> '' then I want to print this line. 

I've been trying to strip flag first from variable names and try concatenate them back in data step. But I don't know if this will work. 

Please let me know if you have any approach to solve this problem. 

[andreas_lds · Accepted solution]

You need two arrays: the first for the flag1-variables (names one), the other one for the flag2-variables (named two, then a loop for checking, the statement "output" to write the observation to the result-dataset and the statement "leave" to avoid duplication.

Here is untested code. Important all flag-variables need to either numeric or alphanumeric for this step to work.

data want;
  set have;

  array one aflag1 bflag1 cflag1;
  array two aflag2 bflag2 cflag2;

  do i = 1 to dim(one);
    if missing(one[i]) and not missing(two[i]) then do;
      output;
      leave;
    end;
  end;
run;

[laiguanyu001]

Hi! Thanks for the quick response. I think this will work. But I'm also wondering, if now I only know that I have aflag1, bflag1, cflag1, can I use this information to find if aflag2, bflag2, cflag2 exists in the data?