how it evaluates ?

[Attyslogin]

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;

when i supply level=4 why its taking expertise = "Medium" instead of "High" ? 

it gives proper output when i define if condition like " level=2 or level=3 " why so ?

curious to know how sas is processing level=2 or 3 ! Thanks !   

[Astounding · Accepted solution]

3 is always true.  It has nothing to do with LEVEL, as if you had coded:

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

In SAS, 0 and missing values are false, and all other numbers are true.

This syntax would work:

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

[PGStats]

SAS is not natural language, it makes fewer assumptions;

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

should be coded as:

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