topic Re: Using the SUBSTRING function in SAS Programming

Using the SUBSTRING function

_maldini_ — Mon, 08 Aug 2016 22:27:41 GMT

I am trying to use the SUBSTRING function to extract a single character from a 60 character string. I want to create 60 new variables (D1, D2, etc.) each containing a sequential digit in the string. In other words, D1 contains the first digit of the string. D2 contains the second digit of the string. D3 contains the 3rd digit of the string, etc. There are multiple observations in the dataset.

My code is inadequate, but pasted below for reference. Thanks for any ideas you may have.

data want (drop=i);
set have;

array D(60);
array seq(60);

do i = 1 to 60;
D[i] = substr(seq[i], 1, 1);
* How do I write this so it will jump from the first position to the next position in the sequence automatically?
end;
run;

Re: Using the SUBSTRING function

Reeza — Mon, 08 Aug 2016 22:38:17 GMT

Use the CHAR() function instead.

CHAR(string, position)

String -> always the same

position -> loop counter, in this case i

SUBSTR(STRING, start, length)

String -> Should always be the same

Start -> loop counter, in this case i

length -> always 1.

D[i] = substr(STRING_VARIABLE, i, 1);

Re: Using the SUBSTRING function

Astounding — Mon, 08 Aug 2016 23:53:44 GMT

One more item you might want to attend to ... assign a length to the new variables:

array D {60} $ 1;

Otherwise, the length of the new variables will default to the same length as the original incoming character string.

Re: Using the SUBSTRING function

RW9 — Tue, 09 Aug 2016 08:43:21 GMT

Could I ask why. It is rarely beneficial to create many variables such as you are doing, in terms of programming. For all your subsequent programming you then need to know how many there are, which could vary. Are you doing some sort of agregates or maths on them, as you can probably do that straight from the string (or if necessary output one row per character). Would make you life much easier.