Example: SELECT WHEN Statement

The SELECT WHEN statement allows you to conditionally process one or more statements within a group of statements based on the value of a single categorical variable. A group of statements between SELECT and END statements is called a SELECT group. SELECT groups contain WHEN statements that identify which SAS^© statements are executed when a particular condition is true. The END statement and at least one WHEN statement are required when specifying the SELECT statement. Using a SELECT group is more efficient than using a series of IF-THEN statements when you have a long series of mutually exclusive conditions. A large number of conditions makes a SELECT group more efficient than IF-THEN/ELSE statements because CPU time is reduced. SELECT groups also make the program easier to read and debug. An optional OTHERWISE statement specifies a statement to execute if no WHEN condition is met. For example, if your data contains missing or invalid data. In null statements used within an OTHERWISE statement, the SELECT WHEN statement prevents SAS^© from issuing an error message.