topic wildcard characters in if/then in SAS Programming

wildcard characters in if/then

beginner — Thu, 11 Feb 2016 18:00:57 GMT

Hi, I'd like to use "wildcards" in an if/then statement, and am wondering if I'm correct in thinking the "%" sign is the wildcard for any character (including numbers that are "type"-ed as "character" and not "numeric" entries). In particular, I'm trying to do the following. I have a dataset A, that looks something like this:

patient blah other variables

Joe aaaa21xy .....

Bob aaaa34zq .....

Tom rsbq76zv .....

From which I want to create a dataset B, containing all patients for which the "blah" variable begins with the characters "aaaa" (and can have any characters after this). In othe words, dataset B would looks like this:

patient blah other variables

Joe aaaa21xy .....

Bob aaaa34zq .....

I tried & failed to do this with the following if/then statement:

data datasetB; set datasetA;
if blah='aaaa%%%%' then output;
run;

I've also tried to use "____" or ":", instead of the "%%%%", and these didn't work either (outputs are all empty datasets). Thanks in advance for your help!

Re: wildcard characters in if/then

slchen — Thu, 11 Feb 2016 18:16:19 GMT

There are some great differences between if and where . Here is one case.

where blah like 'aaaa%';

if blah=:'aaaa';

Re: wildcard characters in if/then

Astounding — Thu, 11 Feb 2016 18:25:34 GMT

A couple of additional notes that might be useful ...

=: does not mean "begins with". It means make the comparison based on whichever string has the shorter length. Ignore any characters beyond that length in the longer string. So these comparisons are identical:

if blah =: 'aaaaa';

if 'aaaaa' =: blah;

Also, you can use =: with the IN operator, with strings of different length:

if blah in ('aaaaa', 'abc', 'bb');

Good luck.

Re: wildcard characters in if/then

beginner — Thu, 11 Feb 2016 23:00:26 GMT

Thank you!