In this chapter, you learned about additional ways to work with data. This chapter covered two main topics: validating and formatting. Validating data means ensuring that the data meets certain rules prior to submitting it for some course of action. This is useful when you want to verify that user input data is in the correct form. Formatting data typically means displaying data to the user in a particular way, such as adding hyphens, parentheses, decimal place separators, and so on.