topic How to check if a character variable consists of all same letters in SAS Procedures

How to check if a character variable consists of all same letters

JamesKauley — Mon, 09 Jan 2012 12:59:35 GMT

Hi, I have a character variable which is about the surname of people. Many respondents entered the names as AA, BBB or ZZZZ which mean that they are not real names. So these cases should be deleted.

Translating this question into this: how can I check if a character variable consists of all same letters? Note that the name has varying length.

Thanks a lot for help.

How to check if a character variable consists of all same letters

art297 — Mon, 09 Jan 2012 13:39:47 GMT

Here is one possibility:

data have;

input name $20.;

cards;

BBB

ZZZZ

AABA

;

data want;

set have;

array chars(20);

do i=1 to length(name);

chars(i)=rank(substr(name,i,1));

end;

if min(of chars(*)) ne max(of chars(*)) then keepit=1;

if keepit;

run;

Re: How to check if a character variable consists of all same letters

Linlin — Mon, 09 Jan 2012 14:08:34 GMT

another way:

data have;

input name $20.;

cards;

BBB

ZZZZ

AABA

;

data want;

set have;

flag=compress(name,substr(name,1,1));

if flag ne ' ';

run;

proc print;

run;

Linlin

How to check if a character variable consists of all same letters

DouglasMartin — Mon, 09 Jan 2012 15:45:19 GMT

This isn't an answer to your question (since the other two respondents gave solutions), but I just wanted to point out that if there is a possibility of pseudonyms like AAA, BBB, etc., I would assume there is also the possibility of pseudonyms like QWERTY, ASDFGH, 12345, etc. You are going to need a more elaborate filter than that (which can not possibly get rid of all pseudonyms without also potentially getting rid of some real names).