Learn Ruby the Hard Way

Preface 1

Acknowledgments 1

The Hard Way Is Easier 2

Reading and Writing 2

Attention to Detail 2

Spotting Differences 3

Do Not Copy-Paste 3

Using the Included Videos 3

A Note on Practice and Persistence 3

A Warning for the Smarties 4

Exercise 0: The Setup 6

Mac OS X 6

Windows 7

Linux 8

Finding Things on the Internet 10

Warnings for Beginners 10

Exercise 1: A Good First Program 12

What You Should See 14

Study Drills 16

Common Student Questions 17

Exercise 2: Comments and Pound Characters 18

What You Should See 18

Study Drills 18

Common Student Questions 19

Exercise 3: Numbers and Math 20

What You Should See 21

Study Drills 21

Common Student Questions 22

Exercise 4: Variables and Names 24

What You Should See 25

Study Drills 25

Common Student Questions 25

Exercise 5: More Variables and Printing 28

What You Should See 28

Study Drills 29

Common Student Questions 29

Exercise 6: Strings and Text 30

What You Should See 31

Study Drills 31

Common Student Question 31

Exercise 7: More Printing 32

What You Should See 32

Study Drills 33

Common Student Questions 33

Exercise 8: Printing, Printing 34

What You Should See 34

Study Drills 35

Common Student Questions 35

Exercise 9: Printing, Printing, Printing 36

What You Should See 36

Study Drills 37

Common Student Questions 37

Exercise 10: What Was That? 38

What You Should See 39

Escape Sequences 39

Study Drills 40

Common Student Questions 40

Exercise 11: Asking Questions 42

What You Should See 42

Study Drills 43

Common Student Question 43

Exercise 12: Prompting People for Numbers 44

What You Should See 44

Study Drills 44

Exercise 13: Parameters, Unpacking, Variables 46

What You Should See 46

Study Drills 47

Common Student Questions 47

Exercise 14: Prompting and Passing 50

What You Should See 50

Study Drills 51

Common Student Questions 51

Exercise 15: Reading Files 52

What You Should See 53

Study Drills 53

Common Student Questions 54

Exercise 16: Reading and Writing Files 56

What You Should See 57

Study Drills 57

Common Student Questions 58

Exercise 17: More Files 60

What You Should See 60

Study Drills 61

Common Student Questions 61

Exercise 18: Names, Variables, Code, Functions 62

What You Should See 63

Study Drills 64

Common Student Questions 65

Exercise 19: Functions and Variables 66

What You Should See 67

Study Drills 67

Common Student Questions 67

Exercise 20: Functions and Files 70

What You Should See 71

Study Drills 71

Common Student Questions 71

Exercise 21: Functions Can Return Something 74

What You Should See 75

Study Drills 75

Common Student Questions 76

Exercise 22: What Do You Know So Far? 78

What You Are Learning 78

Exercise 23: Read Some Code 80

Exercise 24: More Practice 82

What You Should See 83

Study Drills 83

Common Student Questions 83

Exercise 25: Even More Practice 84

What You Should See 85

Study Drills 87

Common Student Questions 87

Exercise 26: Congratulations, Take a Test! 88

Common Student Questions 88

Exercise 27: Memorizing Logic 90

The Truth Terms 90

The Truth Tables 91

Common Student Question 92

Exercise 28: Boolean Practice 94

What You Should See 96

Study Drills 96

Common Student Questions 96

Exercise 29: What If 98

What You Should See 99

Study Drills 99

Common Student Question 99

Exercise 30: Else and If 100

What You Should See 101

Study Drills 101

Common Student Question 101

Exercise 31: Making Decisions 102

What You Should See 103

Study Drills 103

Common Student Questions 103

Exercise 32: Loops and Arrays 106

What You Should See 108

Study Drills 108

Common Student Questions 108

Exercise 33: While Loops 110

What You Should See 111

Study Drills 112

Common Student Questions 112

Exercise 34: Accessing Elements of Arrays 114

Study Drills 115

Exercise 35: Branches and Functions 116

What You Should See 118

Study Drills 118

Common Student Questions 118

Exercise 36: Designing and Debugging 120

Rules for If-Statements 120

Rules for Loops 120

Tips for Debugging 121

Homework 121

Exercise 37: Symbol Review 122

Keywords 122

Data Types 124

String Escape Sequences 124

Operators 125

Reading Code 126

Study Drills 126

Common Student Question 127

Exercise 38: Doing Things to Arrays 128

What You Should See 129

What Arrays Can Do 129

When to Use Arrays 130

Study Drills 131

Common Student Questions 131

Exercise 39: Hashes, Oh Lovely Hashes 132

A Hash Example 133

What You Should See 135

What Hashes Can Do 136

Making Your Own Hash Module 136

The Code Description 140

Three Levels of Arrays 142

What You Should See (Again) 142

When to Use Hashes or Arrays 143

Study Drills 143

Common Student Questions 144

Exercise 40: Modules, Classes, and Objects 146

Modules Are Like Hashes 146

What You Should See 151

Study Drills 151

Common Student Question 151

Exercise 41: Learning to Speak Object Oriented 152

Word Drills 152

Phrase Drills 152

Combined Drills 153

A Reading Test 153

Practice English to Code 156

Reading More Code 156

Common Student Questions 156

Exercise 42: Is-A, Has-A, Objects, and Classes 158

How This Looks in Code 159

Study Drills 161

Common Student Questions 161

Exercise 43: Basic Object-Oriented Analysis and Design 164

The Analysis of a Simple Game Engine 165

Top Down Versus Bottom Up 170

The Code for "Gothons from Planet Percal #25" 170

What You Should See 176

Study Drills 177

Common Student Question 177

Exercise 44: Inheritance Versus Composition 178

What Is Inheritance? 178

Composition 183

When to Use Inheritance or Composition 185

Study Drills 186

Common Student Questions 186

Exercise 45: You Make a Game 188

Evaluating Your Game 188

Function Style 189

Class Style 189

Code Style 190

Good Comments 190

Evaluate Your Game 191

Exercise 46: A Project Skeleton 192

Creating the Skeleton Project Directory 192

Testing Your Setup 195

Using the Skeleton 195

Required Quiz 195

Common Student Questions 196

Exercise 47: Automated Testing 198

Writing a Test Case 198

Testing Guidelines 201

What You Should See 201

Study Drills 202

Common Student Questions 202

Exercise 48: Advanced User Input 204

Our Game Lexicon 204

A Test First Challenge 206

What You Should Test 207

Study Drills 209

Common Student Questions 210

Exercise 49: Making Sentences 212

Match and Peek 212

The Sentence Grammar 213

A Word on Exceptions 213

The Parser Code 213

Playing with the Parser 216

What You Should Test 217

Study Drills 217

Common Student Question 217

Exercise 50: Your First Website 218

Installing Sinatra 218

Make a Simple "Hello World" Project 219

What's Happening Here? 220

Stopping and Reloading Sinatra 221

Fixing Errors 221

Create Basic Templates 222

Study Drills 223

Common Student Questions 223

Exercise 51: Getting Input from a Browser 224

How the Web Works 224

How Forms Work 226

Creating HTML Forms 227

Creating a Layout Template 228

Writing Automated Tests for Forms 229

Study Drills 230

Common Student Question 231

Exercise 52: The Start of Your Web Game 232

Refactoring the Exercise 43 Game 232

Sessions and Tracking Users 237

Creating an Engine 238

Your Final Exam 240

Next Steps 242

How to Learn Any Programming Language 243

Advice from an Old Programmer 246

Appendix: Command Line Crash Course 249

Introduction: Shut Up and Shell 249

The Setup 251

Paths, Folders, and Directories (pwd) 254

If You Get Lost 256

Make a Directory (mkdir) 257

Change Directory (cd) 260

List Directory (ls) 264

Remove Directory (rmdir) 269

Moving Around (pushd, popd) 273

Making Empty Files (Touch, New-Item) 276

Copy a File (cp) 277

Moving a File (mv) 281

View a File (less, MORE) 283

Stream a File (cat) 285

Removing a File (rm) 286

Exiting Your Terminal (exit) 289

Command Line Next Steps 290

Index 291