In this chapter, we have explored a variety of ways to manipulate string variables. Two broad categories have been explored. The first set of functions provide a number of functions with a narrow range of functionality. These functions are relatively straightforward but must often be used together to accomplish complex tasks. The second set of functions make use of regular expressions, and they can be used to accomplish a complex set of tasks using a small number of steps.

In the next chapter, we move on to the topic of working with variables associated with time. This includes translating strings into R's built-in time types, and it also includes the kind of operations that can be performed on time variables.