1 files changed, 81 insertions, 0 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown
index 3a233d98..8723e18f 100644
--- a/ruby.html.markdown
+++ b/ruby.html.markdown
@@ -7,6 +7,7 @@ contributors:
   - ["Luke Holder", "http://twitter.com/lukeholder"]
   - ["Tristan Hume", "http://thume.ca/"]
   - ["Nick LaMuro", "https://github.com/NickLaMuro"]
+  - ["Marcos Brizeno", "http://www.about.me/marcosbrizeno"]
 ---
 
 ```ruby
@@ -286,6 +287,18 @@ surround { puts 'hello world' }
 # }
 
 
+# You can pass a block to a function
+# "&" marks a reference to a passed block 
+def guests(&block)
+ block.call "some_argument" 
+end
+ 
+# You can pass a list of arguments, which will be converted into an array
+# That's what splat operator ("*") is for 
+def guests(*array)
+ array.each { |guest| puts "#{guest}" }
+end
+
 # Define a class with the class keyword
 class Human
 
@@ -339,6 +352,23 @@ dwight.name #=> "Dwight K. Schrute"
 # Call the class method
 Human.say("Hi") #=> "Hi"
 
+# Variable's scopes are defined by the way we name them.
+# Variables that start with $ have global scope
+$var = "I'm a global var"
+defined? $var #=> "global-variable"
+
+# Variables that start with @ have instance scope
+@var = "I'm an instance var"
+defined? @var #=> "instance-variable"
+
+# Variables that start with @@ have class scope
+@@var = "I'm a class var"
+defined? @@var #=> "class variable"
+
+# Variables that start with a capital letter are constants
+Var = "I'm a constant"
+defined? Var #=> "constant"
+
 # Class also is object in ruby. So class can have instance variables.
 # Class variable is shared among the class and all of its descendants.
 
@@ -385,4 +415,55 @@ end
 Human.bar # 0
 Doctor.bar # nil
 
+module ModuleExample
+  def foo
+    'foo'
+  end
+end
+
+# Including modules binds the methods to the object instance
+# Extending modules binds the methods to the class instance
+
+class Person
+  include ModuleExample
+end
+
+class Book
+  extend ModuleExample
+end
+
+Person.foo     # => NoMethodError: undefined method `foo' for Person:Class
+Person.new.foo # => 'foo'
+Book.foo       # => 'foo'
+Book.new.foo   # => NoMethodError: undefined method `foo'
+
+# Callbacks when including and extending a module are executed
+
+module ConcernExample
+  def self.included(base)
+    base.extend(ClassMethods)
+    base.send(:include, InstanceMethods)
+  end
+
+  module ClassMethods
+    def bar
+      'bar'
+    end
+  end
+
+  module InstanceMethods
+    def qux
+      'qux'
+    end
+  end
+end
+
+class Something
+  include ConcernExample
+end
+
+Something.bar     # => 'bar'
+Something.qux     # => NoMethodError: undefined method `qux'
+Something.new.bar # => NoMethodError: undefined method `bar'
+Something.new.qux # => 'qux'
 ```