The Ruby Programming Language

About This Book

As its title implies, this book covers the Ruby programming language and aspires to do so comprehensively and accessibly. This edition of the book covers language versions 1.8 and 1.9. Ruby blurs the distinction between language and platform, and so our coverage of the language includes a detailed overview of the core Ruby API. But this book is not an API reference and does not cover the core classes comprehensively. Also, this is not a book about Ruby frameworks (like Rails), nor a book about Ruby tools (like rake and gem).

This chapter concludes with a heavily commented extended example demonstrating a nontrivial Ruby program. The chapters that follow cover Ruby from the bottom up:

• Chapter 2 covers the lexical and syntactic structure of Ruby, including basic issues like character set, case sensitivity, and reserved words.

• Chapter 3 explains the kinds of data—numbers, strings, ranges, arrays, and so on—that Ruby programs can manipulate, and it covers the basic features of all Ruby objects.

• Chapter 4 covers primary expressions in Ruby—literals, variable references, method invocations, and assignments—and it explains the operators used to combine primary expressions into compound expressions.

• Chapter 5 explains conditionals, loops (including blocks and iterator methods), exceptions, and the other Ruby expressions that would be called statements or control structures in other languages.

• Chapter 6 formally documents Ruby’s method definition and invocation syntax, and it also ...