Although this book is a primer, not an encyclopedia, there are times when we’ll provide supplemental material. You can skip over this material and still complete the tutorial, or you can read the supplemental information if you’d like a better understanding of a topic or why certain choices were made. Supplemental material is set off in a box that looks like this:
Look in these sections for supplemental information and tips.
Information we think you need to know to avoid problems or to make the code work properly is set off in a box that looks like this:
Look in these sections for important information and warnings.
Constant width is used to indicate command-line computer output and code examples, as well as filenames, directories and pathnames, functions, constants, variables, and flow-control statements like
Italics are used to introduce new terms and to indicate URLs.
Constant width bold is used to indicate user input.
You can find information on how to get books or other documents mentioned in a chapter in Appendix A.