Beginning Ruby: From Novice to Professional

476 Pages·2016·13.82 MB·English

by  Peter Cooper

Beginning
ruby
From Novice to Professional
—
Third Edition
—
Peter Cooper
Beginning Ruby
From Novice to Professional

Third Edition
Peter Cooper
Beginning Ruby: From Novice to Professional, Third Edition
Peter Cooper
Louth, Lincs
United Kingdom
ISBN-13 (pbk): 978-1-4842-1279-0 ISBN-13 (electronic): 978-1-4842-1278-3
DOI 10.1007/978-1-4842-1278-3
Library of Congress Control Number: 2016945758
Copyright © 2016 by Peter Cooper
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Contents at a Glance
Foreword ..............................................................................................................xxiii
About the Author .................................................................................................xxvii
About the Technical Reviewer ..............................................................................xxix
Acknowledgments ................................................................................................xxxi
Introduction ........................................................................................................xxxiii
■ Part 1: Foundations and Scaffolding ..................................................1
■ Chapter 1: Let’s Get It Started: Installing Ruby .....................................................3
■ Chapter 2: Programming == Joy: A Whistle-Stop Tour of Ruby and Object
Orientation ...........................................................................................................11
■ Chapter 3: Ruby’s Building Blocks: Data, Expressions, and Flow Control ...........29
■ Chapter 4: Developing Your First Ruby Application .............................................73
■ Chapter 5: The Ruby Ecosystem ..........................................................................93
■ Part 2: The Core of Ruby .................................................................105
■ Chapter 6: Classes, Objects, and Modules .........................................................107
■ Chapter 7: Projects and Libraries ......................................................................149
■ Chapter 8: Documentation, Error Handling, Debugging, and Testing .................163
■ Chapter 9: Files and Databases .........................................................................187
■ Chapter 10: Distributing Ruby Code and Libraries ............................................225
■ Chapter 11: Advanced Ruby Features................................................................243
■ Chapter 12: Tying It Together: Developing a Larger Ruby Application ..............269
v
■ CONTENTS AT A GLANCE
■ Part 3: Ruby Online .........................................................................303
■ Chapter 13: Two Web Application Approaches: Rails and Sinatra .....................305
■ Chapter 14: Ruby and the Internet ....................................................................343
■ Chapter 15: Networking and Sockets ................................................................363
■ Chapter 16: Useful Ruby Libraries .....................................................................379
■ Appendix A: Ruby Primer and Review for Developers .......................................417
■ Appendix B: Useful Resources ...........................................................................443
Index .....................................................................................................................449
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Contents
Foreword ..............................................................................................................xxiii
About the Author .................................................................................................xxvii
About the Technical Reviewer ..............................................................................xxix
Acknowledgments ................................................................................................xxxi
Introduction ........................................................................................................xxxiii
■ Part 1: Foundations and Scaffolding ..................................................1
■ Chapter 1: Let’s Get It Started: Installing Ruby .....................................................3
Installing Ruby ..................................................................................................................4
Windows .................................................................................................................................................4
Mac OS X / macOS .................................................................................................................................6
Linux .......................................................................................................................................................7
Other Platforms ......................................................................................................................................9
Summary ........................................................................................................................10
■ Chapter 2: Programming == Joy: A Whistle-Stop Tour of Ruby and Object
Orientation ...........................................................................................................11
Baby Steps .....................................................................................................................11
irb: Interactive Ruby ..............................................................................................................................12
Ruby Is “English for Computers” ..........................................................................................................12
Why Ruby Makes a Great Programming Language ..............................................................................13
Trails for the Mind .................................................................................................................................14
Turning Ideas into Ruby Code .........................................................................................15
How Ruby Understands Concepts with Objects and Classes ...............................................................15
The Making of a Person ........................................................................................................................16
vii
■ CONTENTS
Basic Variables .....................................................................................................................................17
From People to Pets .............................................................................................................................18
Everything Is an Object ..................................................................................................21
Kernel Methods ....................................................................................................................................22
Passing Data to Methods ......................................................................................................................23
Using the Methods of the String Class .................................................................................................24
Using Ruby in a Non–Object-Oriented Style ...................................................................25
Summary ........................................................................................................................26
■ Chapter 3: Ruby’s Building Blocks: Data, Expressions, and Flow Control ...........29
Numbers and Expressions ..............................................................................................29
Basic Expressions .................................................................................................................................29
Variables ...............................................................................................................................................30
Comparison Operators and Expressions ...............................................................................................31
Looping Through Numbers with Blocks and Iterators ..........................................................................33
Floating Point Numbers ........................................................................................................................35
Constants ..............................................................................................................................................36
Text and Strings .............................................................................................................36
String Literals .......................................................................................................................................36
String Expressions ................................................................................................................................37
Interpolation .........................................................................................................................................39
String Methods .....................................................................................................................................40
Regular Expressions and String Manipulation ......................................................................................41
Arrays and Lists ..............................................................................................................47
Basic Arrays ..........................................................................................................................................47
Splitting Strings into Arrays ..................................................................................................................49
Array Iteration .......................................................................................................................................50
Other Array Methods .............................................................................................................................51
Hashes............................................................................................................................53
Basic Hash Methods .............................................................................................................................53
Hashes Within Hashes ..........................................................................................................................55
viii
■ CONTENTS
Flow Control ...................................................................................................................56
if and unless .........................................................................................................................................56
?, the Ternary Operator .........................................................................................................................57
elsif and case .......................................................................................................................................58
while and until ......................................................................................................................................60
Code Blocks ..........................................................................................................................................61
Other Useful Building Blocks ..........................................................................................62
Dates and Times ...................................................................................................................................62
Large Numbers .....................................................................................................................................65
Ranges ..................................................................................................................................................66
Symbols ................................................................................................................................................68
Converting Objects to Other Classes ....................................................................................................69
Summary ........................................................................................................................70
■ Chapter 4: Developing Your First Ruby Application .............................................73
Working with Source Code Files.....................................................................................73
Creating a Test File ...............................................................................................................................73
A Simple Source Code File ...................................................................................................................75
Running Your Source Code ...................................................................................................................75
Our Application: A Text Analyzer .....................................................................................77
Required Basic Features .......................................................................................................................77
Building the Basic Application ..............................................................................................................78
Obtaining Some Dummy Text ................................................................................................................78
Loading Text Files and Counting Lines .................................................................................................79
Counting Characters .............................................................................................................................80
Counting Words ....................................................................................................................................81
Counting Sentences and Paragraphs ...................................................................................................82
Calculating Averages ............................................................................................................................83
The Source Code So Far .......................................................................................................................84
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