In this chapter, we leave data analysis and return to programming and software development, topics that are the focus of the remaining chapters of the book. In the first chapter, you took a tutorial introduction to R programming, but we left out a lot of details. This chapter will cover many of those details, while the next two chapters will cover more advanced aspects of R programming: functional programming and object-oriented programming.
Expressions
We begin the chapter by going back to expressions. Everything we do in R involves evaluating expressions. Most expressions we evaluate ...
