Characteristics of SAS Programs Next let's look at the individual statements in our sample program. SAS programs are made up of SAS statements. A SAS statement has two important characteristics: It usually begins with a SAS keyword. It always ends with a semicolon. A DATA step begins with the keyword DATA, and a PROC step begins with the keyword PROC. Generally, a step ends with a RUN statement or when a new DATA or PROC step begins. A RUN statement tells SAS to process all the preceding lines of the step.

SAS statements are free-format. This means that they can begin and end anywhere on a line one statement can continue over several lines several statements can be on a line. SAS statements are not case sensitive. Blanks or special characters separate the "words" in a SAS statement.