NOTALPHA() does not return 0 for a string of all alphabetic letters

[yannlee]

DATA Tst;
INPUT Seq $;
Notalphap=NOTALPHA(Seq);
Seql=LENGTH(Seq);
DATALINES;
AbB1
aaaa
Bcc
Cdd
;
RUN;
PROC SQL;
SELECT Seq, Notalphap, Seql
FROM Tst;
QUIT;

I got 

Seq Notalphap Seql

AbB1	4	4
aaaa	5	4
Bcc	4	3
Cdd	4	3

Why is Notalphap not 0 for Seq = aaaa, Bcc, or Cdd?

Thanks.

[Reeza]

Looks like it's finding those spaces at the end based on the length. Use TRIM() to remove the spaces and get the expected value back. 

I agree, not how I would expect the function to work. 

Notalphap=NOTALPHA(trim(Seq));

[yannlee]

Dear Reeza,
Thank you so much.
However TRIM does not work. Please see below.
DATA TST;
INPUT Seq $;
SeqT=TRIM(Seq);
Notalphap=NOTALPHA(Seq);
NotalphaTp=NOTALPHA(SeqT);
Seql=LENGTH(Seq);
SeqTl=LENGTH(SeqT);
DATALINES;
AbB1
aaaa
Bcc
Cdd
;
RUN;
PROC SQL;
SELECT Seq, SeqT, Notalphap, NotalphaTp, Seql, SeqTl
FROM Tst;
QUIT;
I got
Seq SeqT Notalphap NotalphaTp Seql SeqTl
AbB1 AbB1 4 4 4 4
AbB1a AbB1a 4 4 5 5
aaaa aaaa 5 5 4 4
Bcc Bcc 4 4 3 3
Cdd Cdd 4 4 3 3

[yannlee]

I am sorry that the table becomes disarranged after I post it here.

[Kurt_Bremser]

For any text that needs to be posted as-is (log, textual data, results), use this button:

Use the "little running man" right next to it for SAS code.

[SASKiwi · Accepted solution]

The TRIM HAS to be nested inside NOTALPHA. It wont work as a separate statement as SAS will always pad with blank characters to the right of any non-blank characters.

DATA Tst;
INPUT Seq $;
Notalphap=NOTALPHA(trim(Seq));
Seql=LENGTH(Seq);
DATALINES;
AbB1
aaaa
Bcc
Cdd
;
RUN;
PROC SQL;
SELECT Seq, Notalphap, Seql
FROM Tst;
QUIT;

[yannlee]

Dear SASKiwi, Thanks a lot.

[Tom]

Space is NOT an ALPHA character.

SAS stores characters strings as fixed length, padded with space.  Since you did NOT define the length of the variable SEQ before using it in the INPUT statement SAS had to GUESS how to define it so it defined it as length of $8.

[yannlee]

Dear Tom, Thank you.