Conditional Function Definitions

Abstract

An essential aspect of computer programs is their ability to make decisions—to proceed differently depending upon properties of the data they are operating upon. In this chapter, we explore two different ways of building decision-making into Mathematica programs: multiclause definitions, in which a function is defined by more than one rule; and conditional functions, which return one of several values depending upon a condition. These features will greatly expand what we can do with Mathematica; they are also a crucial step toward learning the basic techniques of recursion and iteration.