IS MISSING and IS NOT MISSING Operators in SAS Programming

1. IS MISSING Operator: Selecting Missing Values

   Task 1: Suppose you want to select only those observations in which students did not fill their section information.

   data readin;
   input name $ Section $ Score;
   cards;
   Raj  A 80
   Atul . 77
   Priya B 45
   Sandeep A 95
   Rahul . 84
   Shreya . 44
   ;
   run;
   
   data readin1;
   set readin;
   where Section is missing;
   run;

   Output:
   

   Where Section is missing => This would tell SAS to select missing values for variable SECTION.

2. IS NOT MISSING Operator: Selecting Non-Missing Values

   Task 2: Suppose you want to select only those observations in which students filled their section information.

   data readin;
   input name $ Section $ Score;
   cards;
   Raj  A 80
   Atul . 77
   Priya B 45
   Sandeep A 95
   Rahul . 84
   Shreya C 44
   ;
   run;
   
   data readin1;
   set readin;
   where Section is not missing;
   run;

   Output:
   

   Where Section is not missing => This would tell SAS to select non-missing values.

   The NOT operator can be used with WHERE statement in many other ways:

   • where the section is not missing and the score is missing;

   • where not (score in (34, 44, 84));

   • where not (Score between 50 and 90);

   • where NOT(Section EQ “A”);