So what exactly is a function? You probably have an intuitive notion of
what a function is, but it's hard to write down a single definition because
different people use the word ``function'' to describe different (but related)
things. For example, if you were a mathematician you might say:
``A function is a certain kind of mapping from one set of values to
another set of values.''
And a person who uses Maple might say:
``A function is something that takes one or more values, performs a
computation with those values, and produces a result.''
In this lesson, however, we're most interested in what a C programmer would
say:
``A function is a component of a program. A function takes a list
of argument values, performs a computation with those values, and returns a
single result.''
The last definition tells you that functions are things that can be used to
build programs. You've already used Maple functions to build Maple; today
you'll learn how to do the same thing in C.
Eric N. Eide
Hamlet Project
Department of Computer Science
University of Utah