An array is a temporary grouping of SAS variables that are arranged in a particular order and identified by an array name. Here are several facts about arrays.

An array is a convenient way of temporarily identifying a group of variables. Arrays are often referenced in DO loops because more than one element in an array must be processed.

One reason for using an array is to reduce the number of statements that are required for processing variables. For example, in the DATA step below, the values of seven data set variables are converted from Fahrenheit to Celsius.

data work.report; 
   set master.temps; 
   mon=5*(mon-32)/9; 
   tue=5*(tue-32)/9; 
   wed=5*(wed-32)/9; 
   thr=5*(thr-32)/9; 
   fri=5*(fri-32)/9; 
   sat=5*(sat-32)/9; 
   sun=5*(sun-32)/9; 
run;

The assignment statements perform the same calculation on each variable in this series of statements. Only the name of the variable changes in each statement.

By grouping the variables into a one-dimensional array, you can process the variables in a DO loop. You use fewer statements, and the DATA step program is more easily modified or corrected.

data work.report(drop=day); 
   set master.temps; 
   array wkday{7} mon tue wed thr fri sat sun; 
   do day=1 to 7; 
      wkday{day}=5*(wkday{day}-32)/9; 
   end; 
run;