“If it doesn’t have
to produce correct results,
I can make it arbitrarily fast.”
—Gerald M. Weinberg
This chapter presents the basics of computation. In particular, we discuss how to compute a value from a set of operands (expression), how to choose among alternative actions (selection), and how to repeat a computation for a series of values (iteration). We also show how a particular sub-computation can be named and specified separately (a function). Our primary concern is to express computations in ways that lead to correct and well-organized programs. To help you perform more realistic computations, we introduce the vector type to hold sequences of values.