Contents

• Getting started
  • Getting started with Ruby Language
  • Hello World
  • Hello World as a Self-Executable Fileusing Shebang Unix-like operating systems only
  • Hello World from IRB
  • Hello World without source files
  • Hello World with tk
  • My First Method
• Casting type conversions
  • Casting type conversion
  • Casting to a Float
  • Casting to a String
  • Casting to an Integer
  • Floats and Integers
• Arrays
  • Arrays
  • Create Array of Strings
  • Create Array with Array new
  • Create Array of Symbols
  • Manipulating Array Elements
  • Accessing elements
  • Creating an Array with the literal constructor
  • Decomposition
  • Arrays union intersection and difference
  • Two-dimensional array
  • Inject reduce
  • Filtering arrays
  • Arrays and the splat operator
  • map
  • Turn multi-dimensional array into a one-dimensional flattened array
  • Get unique array elements
  • Get all combinations permutations of an array
  • Remove all nil elements from an array with compact
  • Create an Array of consecutive numbers or letters
  • Create Array of numbers
  • Cast to Array from any object
• Classes
  • Classes
  • Constructor
  • Creating a class
  • Access Levels
  • Accessing instance variables with getters and setters
  • Class Methods types
  • Dynamic class creation
  • New allocate and initialize
  • Class and instance variables
• Hashes
  • Hashes
  • Creating a hash
  • Setting Default Values
  • Accessing Values
  • Automatically creating a Deep Hash
  • Iterating Over a Hash
  • Conversion to and from Arrays
  • Filtering hashes
  • Getting all keys or values of hash
  • Overriding hash function
  • Modifying keys and values
  • Set Operations on Hashes
• Blocks and procs and lambdas
  • Blocks and Procs and Lambdas
  • Lambdas
  • Partial Application and Currying
  • Objects as block arguments to methods
  • Converting to Proc
  • Blocks
  • Proc
• Inheritance
  • Inheritance
  • Subclasses
  • Multiple Inheritance
  • What is inherited
  • Mixins
  • Refactoring existing classes to use Inheritance
• Control flow
  • Control Flow
  • if elsif else and end
  • Case statement
  • Truthy and Falsy values
  • Inline ifunless
  • while until
  • Or-EqualsConditional assignment operator
  • Flip-Flop operator
  • throw catch
  • unless
  • Ternary operator
  • Loop control with break next and redo
  • return vs. next non-local return in a block
  • Control flow with logic statements
  • begin end
• Strings
  • Strings
  • Difference between single-quoted and double-quoted String literals
  • Creating a String
  • Case manipulation
  • Splitting a String
  • String concatenation
  • Positioning strings
  • Joining Strings
  • String starts with
  • String interpolation
  • String ends with
  • Formatted strings
  • String character replacements
  • Understanding the data in a string
  • String Substitution
  • Multiline strings
• Symbols
  • Symbols
  • Creating a Symbol
  • Converting a String to Symbol
  • Converting a Symbol to String
• Exceptions
  • Exceptions
  • Creating a custom exception type
  • Handling multiple exceptions
  • Handling an exception
  • Raising an exception
  • Adding information to custom exceptions
• Thread
  • Thread
  • Basic Thread Semantics
  • Accessing shared resources
  • How to kill a thread
  • Terminating a Thread
• Methods
  • Methods
  • Defining a method
  • Yielding to blocks
  • Default parameters
  • Optional parameters splat operator
  • Single required parameter
  • Required default optional parameter mix
  • Use a function as a block
  • Tuple Arguments
  • Method Definitions are Expressions
  • Capturing undeclared keyword arguments double splat
  • Multiple required parameters
• Method missing
  • method missing
  • Catching calls to an undefined method
  • Use with block
  • Use with parameter
  • Using the missing method
• Numbers
  • Numbers
  • Converting a String to Integer
  • Creating an Integer
  • Rounding Numbers
  • Even and Odd Numbers
  • Converting a number to a string
  • Rational Numbers
  • Complex Numbers
  • Dividing two numbers
• Iteration
  • Iteration
  • Each
  • Implementation in a class
  • Iterating over complex objects
  • For iterator
  • Iteration with index
  • Map
• Regular Expressions and regex based operations
  • Regular Expressions and Regex Based Operations
  • operator
  • Regular Expressions in Case Statements
  • Groups named and otherwise.
  • Quantifiers
  • Character classes
  • Defining a Regexp
  • match - Boolean Result
  • Common quick usage
• Comparable
  • Comparable
  • Rectangle comparable by area
• Gem usage
  • Gem Usage
  • Installing ruby gems
  • Gem installation from githubfilesystem
  • Checking if a required gem is installed from within code
  • Using a Gemfile and Bundler
  • Bundlerinline bundler v1.10 and later
• Design patterns and idioms
  • Design Patterns and Idioms in Ruby
  • Decorator Pattern
  • Observer
  • Singleton
  • Proxy
• Loading source files
  • Loading Source Files
  • Require files to be loaded only once
  • Automatically loading source files
  • Loading optional files
  • Loading files repeatedly
  • Loading several files
• Range
  • Range
  • Ranges as Sequences
  • Iterating over a range
  • Range between dates
• Comments
  • Comments
  • Single Multiple line comments
• Operators
  • Operators
  • Operator Precedence and Methods
  • Case equality operator
  • Safe Navigation Operator
• Operators
  • Operators
  • Comparison Operators
  • Assignment Operators
• Special constants in Ruby
  • Special Constants in Ruby
  • FILE
  • dir
  • PROGRAM NAME or 0
  • Untitled
  • etc
  • ARGV or
  • STDIN
  • STDOUT
  • STDERR
  • stderr
  • stdout
  • stdin
  • ENV
• Modules
  • Modules
  • A simple mixin with include
  • Modules and Class Composition
  • Module as Namespace
  • A simple mixin with extend
• Ruby version manager
  • Ruby Version Manager
  • How to create gemset
  • Installing Ruby with RVM
• Gem creation / management
  • Gem CreationManagement
  • Gemspec Files
  • Building A Gem
  • Dependencies
• Constants
  • Constants
  • Define a constant
  • Modify a Constant
  • Constants cannot be defined in methods
  • Define and change constants in a class
• Variable scope and visibility
  • Variable Scope and Visibility
  • Class Variables
  • Local Variables
  • Global Variables
  • Instance Variables
• rbenv
  • rbenv
  • \1. Install and manage versions of Ruby with rbenv
  • Uninstalling a Ruby
• Environment variables
  • Environment Variables
  • Sample to get user profile path
• Singletons
  • Singleton Class
  • Introduction
  • Inheritance of Singleton Class
  • Singleton classes
  • Accessing Singleton Class
  • Accessing InstanceClass Variables in Singleton Classes
  • Message Propagation with Singleton Class
  • Reopening monkey patching Singleton Classes
• File I/O
  • File and IO Operations
  • Open and closing a file
  • Writing a string to a file
  • get a single char of input
  • Reading from STDIN
  • Reading from arguments with ARGV
• Time
  • Time
  • How to use the strftime method
  • Creating time objects
• Queue
  • Queue
  • Multiple Workers One Sink
  • Converting a Queue into an Array
  • One Source Multiple Workers
  • One Source - Pipeline of Work - One Sink
  • Pushing Data into a Queue - push
  • Pulling Data from a Queue - pop
  • Synchronization - After a Point in Time
  • Merging Two Queues
• Destructuring
  • Destructuring
  • Overview
  • Destructuring Block Arguments
• IRB
  • IRB
  • Basic Usage
  • Starting an IRB session inside a Ruby script
• Enumerators
  • Enumerators
  • Custom enumerators
  • Existing methods
  • Rewinding
• C extensions
  • C Extensions
  • Your first extension
  • Working with C Structs
  • Writing Inline C - RubyInLine
• Struct
  • Struct
  • Creating new structures for data
  • Customizing a structure class
  • Attribute lookup
• Metaprogramming
  • Metaprogramming
  • Implementing with using instance evaluation
  • View an objects methods
  • send method
  • Defining methods dynamically
  • View an objects Instance Variables
  • Instance evaluation
  • View Global and Local Variables
  • View Class Variables
  • Dynamically Creating Methods from Strings
  • Defining methods on instances
• Dynamic evaluation
  • Dynamic Evaluation
  • Evaluating a String
  • Evaluating Inside a Binding
  • Instance evaluation
  • Dynamically Creating Methods from Strings
• instance eval
  • instance eval
  • Instance evaluation
  • Implementing with
• Message passing
  • Message Passing
  • Introduction
  • Message Passing Through Inheritance Chain
  • Message Passing Through Module Composition
  • Interrupting Messages
• Keyword arguments
  • Keyword Arguments
  • Using arbitrary keyword arguments with splat operator
  • Using keyword arguments
  • Required keyword arguments
• DateTime
  • DateTime
  • DateTime from string
  • New
  • Addsubstract days to DateTime
• Truthiness
  • Truthiness
  • All objects may be converted to booleans in Ruby
  • Truthiness of a value can be used in if-else constructs
• JSON with Ruby
  • JSON with Ruby
  • Using JSON with Ruby
  • Using Symbols
• Implicit receives, understanding
  • Implicit Receivers and Understanding Self
  • There is always an implicit receiver
  • Keywords change the implicit receiver
  • When to use self
• Monkey patching
  • Monkey Patching in Ruby
  • Changing an existing ruby method
  • Changing a method with parameters
  • Safe Monkey patching with Refinements
  • Changing any method
  • Extending an existing class
• Introspection
  • Introspection
  • View an objects methods
  • View an objects Instance Variables
  • View Global and Local Variables
  • View Class Variables
• Monkey patching
  • Monkey Patching in Ruby
  • Monkey patching a class
  • Monkey patching an object
• Refinements
  • Refinements
  • Monkey patching with limited scope
  • Dual-purpose modules refinements or global patches
  • Dynamic refinements
• Monkey patching in Ruby
  • Monkey Patching in Ruby
  • Adding Functionality
• Catching exceptions with begin rescue
  • Catching Exceptions with Begin Rescue
  • A Basic Error Handling Block
  • Saving the Error
  • Checking for Different Errors
  • Retrying
  • Checking Whether No Error Was Raised
  • Code That Should Always Run
• Command line apps
  • Command Line Apps
  • How to write a command line tool to get the weather by zip code
• Debugging
  • Debugging
  • Stepping through code with Pry and Byebug
• Pure RSpec JSON API testing
  • Pure RSpec JSON API testing
  • Testing Serializer object and introducing it to Controller
• Recursion
  • Recursion in Ruby
  • Tail recursion
  • Recursive function
• Installation
  • Installation
  • Gems
  • Installing Ruby macOS
  • Linux - Compiling from source
  • LinuxInstallation using a package manager
  • Windows - Installation using installer
  • Linux - troubleshooting gem install
• ERB
  • ERB
  • Parsing ERB
• Introspection
  • Introspection in Ruby
  • Lets see some examples
  • Introspection of class
• Random numbers
  • Generate a random number
  • Sided die
  • Generate a random number from a range inclusive
• Getting started with Hanami
  • Getting started with Hanami
  • About Hanami
  • How to install Hanami
  • How to start the server
• OptionParser
  • OptionParser
  • Mandatory and optional command line options
  • Default values
  • Long descriptions
• Splat operator
  • Splat operator
  • Variable number of arguments
  • Coercing arrays into parameter list
• Multidimensional Arrays
  • Multidimensional Arrays
  • Initializing a 2D array
  • Initializing a 3D array
  • Accessing a nested array
  • Array flattening
• Enumerable
  • Enumerable in Ruby
  • Enumerable module
• Ruby access modifiers
  • Ruby Access Modifiers
  • Instance Variables and Class Variables
  • Access Controls
• Operating system or shell commands
  • Operating System or Shell commands
  • Recommended ways to execute shell code in Ruby
  • Clasic ways to execute shell code in Ruby
• Contributors