Having learned how to use CoffeeScript, you’ll now learn how to use CoffeeScript well. Using a language well means learning how to effectively compose programs, so this part of the book is about learning to express your programs at a higher level and about learning some more advanced idioms that will make your programs easier to write and to comprehend.
Because learning to do things well requires dealing with challenges, some of the topics covered later in this part will require closer reading, and the examples may require more experimentation. To provide you with context for these topics, some of the listings need to be quite long. Take some time to absorb them.