Wrap-Up

In this chapter, you learned how to create recursive methodsi.e., methods that call themselves. You learned that recursive methods typically divide a problem into two conceptual piecesa piece that the method knows how to do (the base case) and a piece that the method does not know how to do (the recursion step). The recursion step is a slightly simpler version of the original problem, and is performed by a recursive method call. You saw some popular recursion examples, including calculating factorials and producing values in the Fibonacci series. You the learned how recursion works "under the hood," including the order in which recursive method calls are pushed on or popped off the program execution stack. Next, you learned the differences between recursive and iterative (non-recursive) methods. In that discussion, you learned that iterative solutions usually use a repetition statement, whereas recursive solutions usually use a selection statement. You learned how to solve more complex problems using recursion, including finding all permutations of a string and displaying fractals. The chapter concluded with an introduction to recursive backtracking, a technique for solving problems that involves backing up through recursive calls to try different possible solutions. In the next chapter, you will learn numerous techniques for sorting lists of data and searching for an item in a list of data, and under what circumstances each searching and sorting technique should be used.