Statistical Analysis System (SAS) Programming Certification Practice Exam

What happens to the values in the Program Data Vector at the end of the DATA step?

1. They are written to a log file.

2. They are output as observations in a dataset.

3. They are discarded.

4. They are set to zero.

The correct answer is: They are output as observations in a dataset.

At the end of the DATA step in a SAS program, the values in the Program Data Vector (PDV) are output as observations in a dataset. The PDV is a temporary area in memory where SAS builds a dataset, row by row, as the DATA step iterates through the data. When a DATA step executes, each iteration of the loop processes a new row of data and updates the values in the PDV accordingly. Once all the processing is complete for a given observation, the contents of the PDV are written to the specified output dataset. This is a crucial aspect of how SAS handles data manipulation; it allows for the creation of structured datasets that can be further analyzed or used in procedures. The other options do not accurately represent what occurs at the conclusion of the DATA step. While log files are important for tracking the execution of code and any errors, they do not receive the PDV values directly. Discarding values or resetting them to zero is not part of the standard procedure when concluding the DATA step. Instead, the primary function is to capture those values as part of the final dataset.