topic Re: Expression evaluating to False but seems it should be True. in SAS Programming

Expression evaluating to False but seems it should be True.

AndyGunn — Sat, 19 Dec 2020 23:52:41 GMT

Any idea why HIT2 is not showing in the log from this code?:

data;
array a (2) a1 a2;
a1 = 1;
a2 = 0;
b = 1;
if b and (a(1) or a(2) or 0) then put 'HIT1';
if b and (a(1) or (a(2) or 0)) then put 'HIT2';
if b and (1 or (0 or 0)) then put 'HIT3';
put _all_;
run;

HIT1
HIT3
a1=1 a2=0 b=1 _ERROR_=0 _N_=1

Re: Expression evaluating to False but seems it should be True.

Tom — Sun, 20 Dec 2020 00:05:10 GMT

Open a ticket with SAS support. Send them this program:

68   data test;
69     array a (2) a1 a2;
70     a1 = 1;
71     a2 = 0;
72     b = 1;
73     put 'ARRAY access  : ' @;
74     if b and (a(1) or (a(2) or 0)) then put 'TRUE'; else put 'FALSE';
75     put 'Direct access : ' @;
76     if b and (a1 or (a2 or 0)) then put 'TRUE'; else put 'FALSE';
77   run;

ARRAY access  : FALSE
Direct access : TRUE
NOTE: The data set WORK.TEST has 1 observations and 3 variables.
NOTE: DATA statement used (Total process time):
      real time           0.01 seconds
      cpu time            0.01 seconds

Re: Expression evaluating to False but seems it should be True.

Kurt_Bremser — Sun, 20 Dec 2020 00:08:20 GMT

Open a track with Technical Support. This looks like a bug to me, and a rather serious one.

Re: Expression evaluating to False but seems it should be True.

novinosrin — Sun, 20 Dec 2020 01:10:42 GMT

Hi @AndyGunn I very very vaguely recall reading this problem illustrated by either Guru's @hashman or @data_null__ the 2 whom I closely follow suggesting to explicitly assign the value when it comes to array references- a(1)=1 , allternatively ^^a(1)/*for boolean*/

if b and (a(1)=1 or (a(2) or 0)) then put 'HIT2';

if b and (^^a(1) or (a(2) or 0)) then put 'HIT2';

However at 7:30pm with a couple of pints I can't remember which one that is. Though my eyes are hazy, I am certain it's one of the above Guru's who once even suggested me to not to play with production codes like I used to otherwise. So -

141  data;
142  array a (2) a1 a2;
143  a1 = 1;
144  a2 = 0;
145  b = 1;
146  if b and (a(1) or a(2) or 0) then put 'HIT1';
147  if b and (a(1)=1 or (a(2) or 0)) then put 'HIT2';
148  if b and (1 or (0 or 0)) then put 'HIT3';
149  put _all_;
150  run;

HIT1
HIT2
HIT3
a1=1 a2=0 b=1 _ERROR_=0 _N_=1
NOTE: The data set WORK.DATA11 has 1 observations and 3 variables.
NOTE: DATA statement used (Total process time):
      real time           0.02 seconds
      cpu time            0.03 seconds

Re: Expression evaluating to False but seems it should be True.

AndyGunn — Sun, 20 Dec 2020 01:33:19 GMT

Thanks much for the response(s). I believe this is my first time ever posting here. Rare to find problems like this - this one was painful. But, I had hope wise people would help. I will open a ticket with SAS.

Re: Expression evaluating to False but seems it should be True.

Ksharp — Sun, 20 Dec 2020 11:46:29 GMT

Very Interesting. It seems ARRAY can't resolve itself and get it's value in CONDITION ,just a symbol refer to a variable.

data test;
array a{2} a1 a2 (1 0);
a1 = 1;
a2 = 0;
b = 1;
put 'ARRAY access : ' @;
if b and (a{1}=1 or (a{2}=1 or 0)) then put 'TRUE'; else put 'FALSE';
put 'Direct access : ' @;
if b and (a1 or (a2 or 0)) then put 'TRUE'; else put 'FALSE';
run;

ARRAY access : TRUE
Direct access : TRUE

Re: Expression evaluating to False but seems it should be True.

AndyGunn — Mon, 21 Dec 2020 23:08:41 GMT

Hello novinosrin, I did use the '=1' shown in your example code to get my job working for now. Was cleaner than things I was thinking of. Have not heard back from SAS yet. Track 7613246087. Thanks, Andy