What type of variables can an ARRAY contain?

An ARRAY in SAS can only contain variables of the same type, which is essential for its operation. When you declare an ARRAY, it is designed to simplify the processing of a set of variables that share common characteristics, typically in terms of their data type.

Using an ARRAY allows you to iterate over these variables easily, applying the same operation across all the variables, such as calculations or transformations. This functional design depends on the assumption that all the variables are either numeric or character; mixing types would complicate the logic and functionality of the ARRAY. For instance, if you attempt to create an ARRAY that mixes numeric and character variables, you would encounter errors or unexpected results since operations applicable to numeric data types would not work with character data types and vice versa.

In contrast, the other options suggest either including variables of different data types or being restricted to one type alone (numeric or character), which does not align with the fundamental structure and purpose of an ARRAY in SAS. Thus, the correct understanding of an ARRAY is that it is strictly for variables of the same type.