topic Re: else if in SAS Programming

else if

nish1017 — Sat, 25 Feb 2017 08:23:32 GMT

Obsname level :

Frank 1

Joan 2

Sui 2

Jose 3

Burt 4

Kelly .

Juan 1

The following SAS program is submitted:

data work . expertise;

set work. levels;

if level = . then expertise = 'Unknown';

else if level = 1 then expertise = 'Low';

else if level = 2 or 3 then expertise =' Medium';

else expertise = 'High';

run;

Which of the following values does the variable EXPERTISE contain?

A. Low, Medium, and High only
B. Low, Medium, and Unknown only
C. Low, Medium, High, and Unknown only
D. Low, Medium, High, Unknown, and ' ' (missing character value)

Can anyone help me with its answer with a reasoning

Re: else if

mkeintz — Sat, 25 Feb 2017 07:58:51 GMT

Do you have SAS? Why not run a program and see?

Re: else if

nish1017 — Sat, 25 Feb 2017 08:22:11 GMT

I have, but somehow not getting the logic. Just want to know why expertise level of 'High' wont come, as there is clearly a level of 4 stated in this problem. This was one of the questions posted on the forums earlier, but didnt find a convincing answer there. Would be great if you can help me understand the logic. Specifically I am stuck as to why the else if NOT generate 'High' as an output in the problem.

Re: else if

mkeintz — Sat, 25 Feb 2017 08:29:09 GMT

The statement

else if level = 2 or 3 then expertise =' Medium';

does NOT mean

else if level=2 or level=3 then expertise='Medium':

That's because the clause "or 3" is really a logical expression "or [some condition not=0]". Only zero is false, so 3 must ALWAYS be true. As a result the "medium" ends up getting everything the failed the prior 2 IF tests.

You could use

else if level in (2,3) then expertise='Medium';

Re: else if

jklaverstijn — Sat, 25 Feb 2017 14:58:31 GMT

I didn't run the code myself buy this looks suspicious:

 else if level = 2 or 3 then expertise =' Medium';

That is not the same as

if (level=2 or level=3)

What SAS sees is

else if 3

which is always true. So the else after that is never executed.

Regards,

- Jan

Re: else if

nish1017 — Sat, 25 Feb 2017 16:04:57 GMT

I got it ! I was considering it as
if (level=2 or level=3) WHICH is not the case. I got this thing clear now .

Re: else if

nish1017 — Sat, 25 Feb 2017 16:06:31 GMT

Thanks jklaverstijn. I mixed up exactly in the thing you pointed out/