topic Re: How to use SUBSTRN in macro function as used in data step in SAS Programming

How to use SUBSTRN in macro function as used in data step

raja777pharma — Sat, 26 Jun 2021 10:29:05 GMT

Hello ,

I would like to use 'SUBSTRN' in macro code , but when use this one gettng errors.

we can use %ksubstr in macro , but how to use 'SUBSTRN' in macro code.

Below is my exist code in data step , but would like to write in macro code to assing macro varible value.

%let titles=listing 16-88.4. many text many text words;
%let title1= Subject listing by devations;
data  test;
  titles=symget('titles');
  title1=symget(title1);
  file_title1=substrn(titles,1,find(titles,' ')),title1);
run;
output is = file_title1="listing 16-88.4. Subject listing by devations";

woudl like to write above cod in macro to assing to macor varible like below but i am getting errors, please help me to for this issue, but not use cally symput in data step to create macro varible or proc sql.

%let file_title1=%ksubstrn(&titles,1,%kfind(&titles,' ')&title1);

Re: How to use SUBSTRN in macro function as used in data step

PaigeMiller — Sat, 26 Jun 2021 10:37:11 GMT

You need to enclose SUBSTRN (or any data step function) inside %sysfunc

%let file_title1 = %sysfunc(substrn(&titles,1,%kfind(&titles,' ')&title1));

Re: How to use SUBSTRN in macro function as used in data step

Astounding — Sat, 26 Jun 2021 11:00:45 GMT

Does the beginning of &TITLES always contain a number in the form ##.#. ? If so, you could use a direct approach:

%let file_title1 = %scan(&titles, 1, .).%scan(&titles, 2, .).  &title1;

Re: How to use SUBSTRN in macro function as used in data step

Tom — Sat, 26 Jun 2021 11:53:12 GMT

Been there. Done that.

%substrn()

%qsubstrn()

Re: How to use SUBSTRN in macro function as used in data step

ErikLund_Jensen — Sun, 27 Jun 2021 09:41:26 GMT

Hi @raja777pharma

We need to take this in several steps.

First thing is that your data step doesn't work. There are two errors:

You dont' get a value in title1, because the argument to symget should be quoted like in the line above.
The substrn function takes max. 3 arguments, but you have added title1 as a fourth argument. If you want to concatenate the value of title1 to the substring, you need to use either a concatenation operator or a CAT function.

Then I need to ask a question about your wanted output, because when the errors are fixed, the result is:

I expect your wanted output to be the string "listing 16-88.4. Subject listing by devations", but that is not what you get, because you take a substring from start to first blank character, so the number part is omitted. And a move from a data step to macro code wouldn't change that.

It would be easier to forget about substringing and use scan instead, so you can pick the strings you want regardless of length:

%let titles=listing 16-88.4. many text many text words;
%let title1= Subject listing by devations;
%let file_title = %scan(&titles,1,%str( )) %scan(&titles,2,%str( )) &title1;

This gives:

listing 16-88.4. Subject listing by devations

Good luck

Erik

, because the not what you get from your data step. You take a substring from start to first blank character, so the step actually gives