cawel

irb(main):001:0> 3.to_i
=> 3

irb(main):002:0> Integer(4)
=> 4

irb(main):003:0> "not_an_int".to_i
=> 0

irb(main):004:0> Integer("not_an_int")

cawel

#instance-specific behavior
puts "kind of Scrollable? #{pane.kind_of?(Scrollable)}"
pane.extend(Scrollable)
pane.scroll 3
puts pane.position
puts "kind of Scrollable? #{pane.kind_of?(Scrollable)}"

#adding behavior to the class

class Pane

cawel

module Scrollable
  def scroll offset
    # scrollling code
  end
end

class Pane
  attr_accessor :content
  def initialize content
    @content = content

cawel

class Test

  def public_method
    t = Test.new
    t.private_method # illegal (throws NoMethodError)
  end

  private

  def private_method

cawel

class Test
  
  def self.main
    Test.new.method  #illegal (throws NoMethodError)
  end
  
  private

  def method
    puts "private method called"

cawel

public class Test{
  private void method(){ System.out.println("method called"); }

  public static void main(String[] args){
    Test test = new Test();
    test.method();
  }
}

cawel

hash = Hash.new
# hash.has_key? 'no_such_key' => false
# default value is implicitly set to nil
# hash['no_such_key'] => nil
# hash.has_key? 'no_such_key' => false


hash = Hash.new(0)
# hash.has_key? 'no_such_key' => false
# default value is explicitly set (to 0 here)

cawel

require 'rubygems'
require 'active_support'

class Time
  @@WEEKDAYS = (1..5)

  def next_business_day days_count = 1
    day = self
    days_count.times do
      begin

cawel

require 'test/unit'
require 'rubygems'
require 'active_support'
require 'business_days' #the monkey patch code to be tested 

class TestBusinessDays < Test::Unit::TestCase

  def setup
    @monday =    Time.mktime(2008, 7, 14, 0, 0, 0)
    @wednesday = Time.mktime(2008, 7, 16, 0, 0, 0)

cawel

class Decorator

  def initialize(subject)
    subject.public_methods(false).each do |meth|
      (class << self; self; end).class_eval do
        define_method meth do |*args|
          subject.send meth, *args
        end
      end
    end