Java™ How To Program (Early Objects), Tenth Edition

Section 18.2 Recursion Concepts

• When a recursive method is called (p. 778) to solve a problem, it can solve only the simplest case(s), or base case(s). If called with a base case (p. 778), the method returns a result.

• If a recursive method is called with a more complex problem than a base case, it typically divides the problem into two conceptual pieces—a piece that the method knows how to do and a piece that it does not know how to do.

• To make recursion feasible, the piece that the method does not know how to do must resemble the original problem, but be a slightly simpler or smaller version of it. Because this new problem resembles the original problem, the method calls a fresh copy of itself to work on the smaller problem—this is called ...