Java, A Beginner's Guide, 5th Edition, 5th Edition

Recursion

In Java, a method can call itself. This process is called recursion, and a method that calls itself is said to be recursive. In general, recursion is the process of defining something in terms of itself and is somewhat similar to a circular definition. The key component of a recursive method is a statement that executes a call to itself. Recursion is a powerful control mechanism.

The classic example of recursion is the computation of the factorial of a number. The factorial of a number N is the product of all the whole numbers between 1 and N. For example, 3 factorial is 1 × 2 × 3, or 6. The following program shows a recursive way to compute the factorial of a number. For comparison purposes, a nonrecursive equivalent is also included. ...