Ruby Essentials

Ruby Essentials is a free on-line book designed to provide a concise and easy to follow guide to learning Ruby.

1. About Ruby Essentials
   
   
2. What is Ruby?
   • The History of Ruby
   • What is Ruby?
   • Why is Ruby so Popular?
     
     
3. Getting and Installing Ruby
   • Installing Ruby on Linux
   • Ruby on Red Hat Enterprise and Fedora Linux
   • Ruby on Ubuntu and Debian Linux
   • Ruby on Microsoft Windows
     
     
4. Simple Ruby Examples
   • The Most Basic Ruby Example
   • Executing Ruby from the Command Line
   • Interactive Ruby Execution
   • Executing Ruby from a File
   • Creating a Self Contained Ruby Executable on Linux or UNIX
   • Associating Ruby Files on Windows
     
     
5. Commenting Ruby Code
   • What is Exactly is Commenting
   • Single Line Ruby Comments
   • Comments on Lines of Code
   • Multi Line or Block Ruby Comments
     
     
6. Understanding Ruby Variables
   • Ruby Constants
   • Ruby and Variable Dynamic Typing
   • Declaring a Variable
   • Identifying a Ruby Variable Type
   • Changing Variable Type
   • Converting Variable Values
     
     
7. Ruby Variable Scope
   • What is Variable Scope?
   • Detecting the Scope of a Ruby Variable
   • Ruby Local Variables
   • Ruby Global Variables
   • Ruby Class Variables
   • Ruby Instance Variables
   • Ruby Constant Scope
     
     
8. Ruby Number Classes and Conversions
   • Ruby Number Classes
   • Converting Numbers in Ruby
     
     
9. Ruby Methods
   • Declaring and Calling a Ruby Method
   • Passing Arguments to a Method
   • Passing a Variable Number of Arguments to a Method
   • Returning a Value from a Function
   • Ruby Method Aliases
     
     
10. Ruby Ranges
    • Ruby Sequence Ranges
    • Using Range Methods
    • Ruby Ranges as Conditional Expressions
    • Ruby Range Intervals
    • Ranges in case Statements
      
      
11. Understanding Ruby Arrays
    • What is a Ruby Array
    • How to Create a Ruby Array
    • Populating an Array with Data
    • Finding Out Information About a Ruby Array
    • Accessing Array Elements
    • Finding the Index of an Element
      
      
12. Advanced Ruby Arrays
    • Combining Ruby Arrays
    • Intersection, Union and Difference
    • Identifying Unique Array Elements
    • Pushing and Popping Array Elements
    • Ruby Array Comparisons
    • Modifying Arrays
    • Deleting Array Elements
    • Sorting Arrays
      
      
13. Ruby Operators
    • The Anatomy of a Ruby Operation
    • Performing Ruby Arithmetic using Operators
    • Ruby Assignment Operators
    • Parallel Assignment
    • Ruby Comparison Operators
    • Ruby Bitwise Operators
      
      
14. Ruby Operator Precedence
    • An Example of Ruby Operator Precedence
      
      
15. Ruby Math Functions and Methods
    • Ruby Math Constants
    • Ruby Math Methods
    • Some Examples
      
      
16. Understanding Ruby Logical Operators
    
    
17. Ruby Object Oriented Programming
    • What is an Object?
    • What is a Class?
    • Defining a Ruby Class
    • Creating an Object from a Class
    • Instance Variables and Accessor Methods
    • Ruby Class Variables
    • Instance Methods
    • Ruby Class Inheritance
      
      
18. Ruby Flow Control
    • The Ruby if Statement
    • Using else and elsif Constructs
    • The Ruby Ternary Operator
      
      
19. The Ruby case Statement
    • Number Ranges and the case statement
      
      
20. Ruby While and Until Loops
    • The Ruby While Loop
    • Breaking from While Loops
    • unless and until
      
      
21. Looping with for and the Ruby Looping Methods
    • The Ruby for Loop
    • The Ruby times Method
    • The Ruby upto Method
    • The Ruby downto Method
      
      
22. Ruby Strings - Creation and Basics
    • Creating Strings in Ruby
    • Quoting Ruby Strings
    • General Delimited Strings
    • Ruby Here Documents
    • Getting Information About String Objects
      
      
23. Ruby String Concatenation and Comparison
    • Concatenating Strings in Ruby
    • Freezing a Ruby String
    • Accessing String Elements
    • Comparing Ruby Strings
    • Case Insensitive String Comparisons
      
      
24. Ruby String Replacement, Substitution and Insertion
    • Changing a Section of a String
    • Ruby String Substitution
    • Repeating Ruby Strings
    • Inserting Text Into a Ruby String
    • Ruby chomp and chop Methods
    • Reversing the Characters in a String
      
      
25. Ruby String Conversions
    • Converting a Ruby String to an Array
    • Changing the Case of a Ruby String
    • Performing String Conversions
      
      
26. Ruby Directory Handling
    • Changing Directory in Ruby
    • Creating New Directories
    • Directory Listings in Ruby
      
      
27. Working with Files in Ruby
    • Creating a New File with Ruby
    • Opening Existing Files
    • Renaming and Deleting Files in Ruby
    • Getting Information About Files
    • Reading and Writing Files
      
      
28. Working with Dates and Times in Ruby
    • Accessing the Date and DateTime Classes in Ruby
    • Working with Dates in Ruby
    • Calculating the Difference Between Dates
      
      
29. Useful Ruby Links and Resources