Using the External File Name to Create File Date Variables
Creating a file date for each input file, when one does not exist in the file, becomes a tedious task as the number of files grows. Different methods can be used, such as reading in all the files at once, using a file counter, the Job File Control Block (JFCB), and implementing macros. The key was to find a solution that reduces both the programmer's time and CPU time. When all methods were compared to reading in each file in its own data step, the file counter and JFCB both increased CPU time, but decreased the amount of hard coding necessary, while using a macro decreased the amount of hard coding and CPU time.