In this chapter, you will learn how to create the S3 and S4 objects and how to use them in a variety of applications. Specifically, you will orient yourself using the following recipes:

• Defining a new S3 class
• Defining methods for the S3 class
• Creating a generic function and defining a method for the S3 class
• Defining a new S4 class
• Defining methods for an S4 class
• Creating a function to return an object of the S4 class