Ruby Pocket Reference, 2nd Edition

Chapter 1. Ruby Pocket Reference

Introduction

Ruby is an open source, object-oriented scripting language created by Yukihiro “Matz” Matsumoto and initially released in Japan in 1995. Ruby has since gained worldwide acceptance as an easy-to-learn, powerful, and expressive programming language. An interpreted language, Ruby runs on all major platforms. For the latest information on Ruby, see http://www.ruby-lang.org. For online Ruby documentation, see http://ruby-doc.org.

This edition of the Ruby Pocket Reference supports version 2.2.2 of Ruby, the current version at the time of writing.

Conventions Used in This Book

The following typographical conventions are used in this book:

Italic

Indicates new terms, URLs, email addresses, filenames, and file extensions.

Constant width

Used for program listings, as well as within paragraphs to refer to program elements such as variable or function names, databases, data types, environment variables, statements, and keywords.

Constant width bold

Shows commands or other text that should be typed literally by the user.

Constant width italic

Shows text that should be replaced with user-supplied values or by values determined by context.

Note

This element signifies a general note.

Using Code Examples

Supplemental material (code examples, exercises, etc.) is available for download at https://github.com/michaeljamesfitzgerald/Ruby-Pocket-Reference-2nd-Edition.

This book is here to help you get your job done. In general, if example ...