In DATA step programming, you often need to perform the same action on more than one variable. Although you can process variables individually, it is easier to handle them as a group. You can do this by using array processing.

For example, using an array and DO loop, the program below eliminates the need for 365 separate programming statements to convert the daily temperature from Fahrenheit to Celsius for the year.

     data work.report;
        set master.temps;
        array daytemp(365) day1-day365;
        do i=1 to 365;
           daytemp(i)=5*(daytemp(i)-32)/9;
        end;
     run;

This lesson teaches you how to define an array and reference elements of the array in the DATA step.

This lesson contains 30 pages and takes approximately 45-60 minutes to complete.

Objectives

After completing this lesson, you will be able to

• group variables into one- and two-dimensional arrays
• perform an action on array elements
• create new variables using an ARRAY statement
• assign initial values to array elements
• create temporary array elements using an ARRAY statement.

Prerequisites

Before taking this lesson, you should have completed the following lessons:

Getting Started with SAS Programming

• Working in the SAS Environment
• Basic Concepts
• Editing and Debugging SAS Programs
• Setting Up Your SAS Session

Creating and Modifying Variables

• Creating Variables
• Formatting Variable Values

DATA Step Processing

• Debugging and Testing DATA Steps
• Generating Data with DO Loops