A custom function
is a developer-defined formula that expands on the built-in functions within the database it is installed. Formulas can be off-loaded away from individual formulas and placed into a custom central library of easily accessible functionality. Unlike regular formulas, custom functions can be defined to accept parameters, can be recursive, and can be accessed directly from any formula or script in the database. A well-designed, open-ended, reusable custom function can reduce redundancies in formulas, simplify calculations, and save time. In this chapter, we discuss ...