《Effective Ruby(編寫高質量Ruby代碼的48個
有效方法英文版)》是作者瓊斯近十年Ruby開發經驗
的結晶。書中為Ruby開發的每個主要領域提供了切實
可行的建議，從模塊到內存，再到元編程。作者利用
48個Ruby實戰案例，揭示了Ruby鮮有人知的風格、特
色、缺陷，以及對代碼行為和執行極具影響的復雜性
。每種實踐方法都包含了具體的、實用的、組織清晰
的指導方針，細致的建議，詳細的專業理由，以及詳
盡的示例代碼講解。
本書旨在通過全面地介紹Ruby編程技術，幫助
Ruby程序員及愛好者寫出更健壯、更高效、更易維護
和運行的代碼。

序言
前言
致謝
關於作者
Chapter 1: Accustoming Yourself to Ruby
Item 1: Understand What Ruby Considers to Be True
Item 2: Treat All Objects as If They Could Be nil
Item 3: Avoid Ruby’s Cryptic Perlisms
Item 4: Be Aware That Constants Are Mutable
Item 5: Pay Attention to Run-Time Warnings
Chapter 2: Classes, Objects, and Modules
Item 6: Know How Ruby Builds Inheritance Hierarchies
Item 7: Be Aware of the Different Behaviors of super
Item 8: Invoke super When Initializing Subclasses
Item 9: Be Alert for Ruby’s Most Vexing Parse
Item 10: Prefer Struct to Hash for Structured Data
Item 11: Create Namespaces by Nesting Code in Modules
Item 12: Understand the Different Flavors of Equality
Item 13: Implement Comparison via “＜=＞” and the Comparable Module
Item 14: Share Private State through Protected Methods
Item 15: Prefer Class Instance Variables to Class Variables
Chapter 3: Collections
Item 16: Duplicate Collections Passed as Arguments before Mutating Them
Item 17: Use the Array Method to Convert nil and Scalar Objects into Arrays
Item 18: Consider Set for Efficient Element Inclusion Checking
Item 19: Know How to Fold Collections with reduce
Item 20: Consider Using a Default Hash Value
Item 21: Prefer Delegation to Inheriting from Collection Classes
Chapter 4: Exceptions
Item 22: Prefer Custom Exceptions to Raising Strings
Item 23: Rescue the Most Specific Exception Possible
Item 24: Manage Resources with Blocks and ensure
Item 25: Exit ensure Clauses by Flowing Off the End
Item 26: Bound retry Attempts, Vary Their Frequency, and Keep an Audit Trail
Item 27: Prefer throw to raise for Jumping Out of Scope
Chapter 5: Metaprogramming
Item 28: Familiarize Yourself with Module and Class Hooks
Item 29: Invoke super from within Class Hooks
Item 30: Prefer define_method to method_missing
Item 31: Know the Difference between the Variants of eval
Item 32: Consider Alternatives to Monkey Patching
Item 33: Invoke Modified Methods with Alias Chaining
Item 34: Consider Supporting Differences in Proc Arity
Item 35: Think Carefully Before Using Module Prepending
Chapter 6: Testing
Item 36: Familiarize Yourself with MiniTest Unit Testing
Item 37: Familiarize Yourself with MiniTest Spec Testing
Item 38: Simulate Determinism with Mock Objects
Item 39: Strive for Effectively Tested Code
Chapter 7: Tools and Libraries
Item 40: Know How to Work with Ruby Documentation
Item 41: Be Aware of IRB’s Advanced Features
Item 42: Manage Gem Dependencies with Bundler
Item 43: Specify an Upper Bound for Gem Dependencies
Chapter 8: Memory Management and Performance
Item 44: Familiarize Yourself with Ruby’s Garbage Collector
Item 45: Create Resource Safety Nets with Finalizers
Item 46: Be Aware of Ruby Profiling Tools
Item 47: Avoid Object Literals in Loops
Item 48: Consider Memoizing Expensive Computations
Epilogue
Index