Within a DATA step, what does the STOP statement do?

The STOP statement within a DATA step is utilized to end the execution of that DATA step immediately. When the STOP statement is encountered, the program stops processing the current DATA step and does not execute any further statements within that DATA step, nor does it proceed to create any output datasets. This can be particularly useful for debugging or controlling the flow of execution under specific conditions without completing the entire DATA step.

In practical scenarios, inserting a STOP statement can help users interrupt the data processing and examine the state of the program at that point. It's important to remember that once the STOP statement is reached, control does not transfer to the next observation or to any other statements in the current DATA step. Understanding this function is essential for anyone working with DATA steps, as it can affect how and when data is processed and outputted.