QUESTION: Is there any systemic reason in the SAS Base 9.4 programming model, why the logical expression BETWEEN-AND cannot be used in IF-THEN and in SELECT-WHEN statements?   BETWEEN-AND seem to be working only in WHERE statements and when used in IF-THEN or SELECT-WHEN there are errors reported. Does it mean that BETWEEN-AND expression has some kind of a special status within SAS Base 9.4?   Example   First we create a sample data set WORK.test where we have only one numeric variable (column) Order_ID.     data WORK.test; INFILE DATALINES; INPUT Order_ID : 12.; DATALINES; 1 2 3 4 5 6 7 8 9 10 ;;; run;     Then we would like to output to a new data set work.test2 only observations which have value ORDER_ID between 5 and 7.   We can approach this in two ways: Scenario #1: filter input data using WHERE clause Scenario #2: control output using either IF-THEN statement or SELECT-WHEN statement Let's start with Scenario #1   Using 5 <= Order_ID <=7   DATA work.test2; SET work.test; WHERE (5 <= Order_ID <= 7); RUN; or using Order_ID BETWEEN 5 AND 7   DATA work.test2; SET work.test; WHERE (Order_ID BETWEEN 5 AND 7); RUN; generates exactly the same result:         But when we follow the Scenario #2 (controlling the output with IF-THEN or with SELECT-WHEN), we will get the following results:   DATA work.test2; SET work.test; IF (5 <= Order_ID <= 7) THEN OUTPUT; RUN; and DATA work.test2; SET work.test; SELECT; WHEN (5 <= Order_ID <= 7) OUTPUT; OTHERWISE; END; RUN; both generate the expected data set:   but using the logical expression BETWEEN-AND will generate errors when used in IF-THEN and in SELECT-WHEN statements:     DATA work.test2; SET work.test; IF (Order_ID BETWEEN 5 AND 7) THEN OUTPUT; RUN; we get error messages:    ERROR 388-185: Expecting an arithmetic operator. ERROR 202-322: The option or parameter is not recognized and will be ignored.   and    DATA work.test2; SET work.test; SELECT; WHEN (Order_ID BETWEEN 5 AND 7) OUTPUT; OTHERWISE; END; RUN; we get error messages:  ERROR 388-185: Expecting an arithmetic operator. ERROR 202-322: The option or parameter is not recognized and will be ignored.   The above examples have been tested in SAS Studio 9.4.   I am looking forward to feedback from more experienced SAS Programmers.   Is it a feature or a bug? 😉   Thank You.   ... View more