topic Re: Concatenating Strings in SAS Programming

Concatenating Strings

Davanden — Mon, 06 Nov 2017 15:23:54 GMT

I am trying to take a list of text items associated with key values and concatenate them into semicolon-delimited lists. Instead, I'm getting lists of semicolons only. I can't figure out what is going wrong. This is SAS 9.4 for Windows.

ODS HTML;
DATA HAVE;
     INPUT Key $ 1 Text $ 3-20;
     CARDS;
A Alpha One
A alpha two
A Alpha 3
B bee one
C See me
C See you
;;;
RUN;

PROC SORT DATA=Have;
     by Key;
run;

PROC PRINT;
     TITLE Have;
RUN;

DATA NotWhatIWant (KEEP=Key List);
     SET HAVE;
     BY Key;
     LENGTH List $50;
     RETAIN LIST;
     IF first.key THEN
          LIST = ' ';
     LIST = CATX(List,';',Text);
     IF LAST.KEY THEN
          OUTPUT NotWhatIWant;
RUN;

PROC PRINT DATA=NotWhatIWant;
     TITLE Not What I Want;
RUN;
ODS CLOSE;

Re: Concatenating Strings

LinusH — Mon, 06 Nov 2017 14:53:52 GMT

Are your sure that HAVE is looking good?
Use put statements or the data step debugger to analyze your variables during execution.

Re: Concatenating Strings

Astounding — Mon, 06 Nov 2017 14:57:35 GMT

When using CATX, the first parameter (not the second) should be the delimiter.

Re: Concatenating Strings

RW9 — Mon, 06 Nov 2017 15:27:40 GMT

You were nearly there, I update your code. Do avoid coding all in uppercase or mixed case, its really hard to read.

proc sort data=have;
  by key;
run;

data notwhatiwant (keep=key list);
  set have;
  by key;
  length list $50;
  retain list;
  list=ifc(first.key,'',catx(';',list,text));
  if last.key;
run;

Note how I use ifc() boolean function to simplfy the if, and you do not need the output notwhatiwant.

Re: Concatenating Strings

juliet_scott — Mon, 29 Oct 2018 10:35:35 GMT

The old-fashioned way of concatenating strings uses the operator “||”. This is still available, and still perfectly respectable. When using it, it is important to be aware of the lengths of the variables involved.

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