Selecting partial string within array do loop

[tolsabeck]

Hello, I am using SAS 9.4 and I have a dataset with secondary diagnosis ICD10 codes. There are up to 120 secondary diagnosis codes listed. My goal is to build an array for the diagnosis codes and create a flag for any secondary diagnosis with a mention of alcohol. All the alcohol diagnosis codes start with an 'F10___' but depending on the specifics the code could be 3 more digits and there are too many ICD10 codes to just manually type out. I am trying to write a code to flag the observations with an alcohol related code associated to it by creating an array then doing a do loop that will select a partial string from the 120 variable array. I am not getting an error but my results come back as 0 observations which I know is incorrect based on spot checking one of the secondary code variables. Below is the code I am working with. 

data cancer3;
set cancer;
array CDiagcode {1:120} DX1-DX120; *build array of DX codes;
 do j = 1 to 120;                 
      if CDiagcode {j} = FIND(of CDiagcode{j}, 'F10') then do;
   *if secondary diagnosis is for alcohol*;
            substance10 = 1;
            SFlag = 1;                     *flag 2;
      end;
      else if SFlag not in (1) then do; *if no alcohol diagnosis DM = 0;
            substance10 = 0;
            SFlag = 0;                     *flag 3;
      end;
 end;
run;

[Reeza · Accepted solution]

At first glance, this line is wrong:

if CDiagcode {j} = FIND(of CDiagcode{j}, 'F10') then do;

The code will never match the results from the FIND, which returns a number and your array is likely text values. I'm guessing your log has a ton of errors or warnings? Can you post the log?

You likely want something similar to :

if cdiagcode(j) =: 'F10' then do;

[tolsabeck]

Thank you! The code I posted actually didn't result in any errors in the log. It just output the wrong answer. Adjusting it to your suggestion provided something that looks more correct.