Let's Learn Ruby - Basic
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This document provides an overview of the Ruby programming language. It introduces basic Ruby concepts like variables, data types, flow control, classes and objects. It also discusses tools and frameworks like Rails, gems, and testing. The document encourages learning Ruby and provides resources to get started, including trying an interactive tutorial and installing a development environment. It emphasizes that Ruby is fun and easy to learn.
![Let’s Learn Ruby
Array.new v.s []](https://image.slidesharecdn.com/letslearnruby-131230165323-phpapp01/85/Let-s-Learn-Ruby-Basic-83-320.jpg)
![Let’s Learn Ruby
Exercise
please sort a given array [1, 3, 4, 1, 7, nil, 7],
and remove nil and duplicate number.](https://image.slidesharecdn.com/letslearnruby-131230165323-phpapp01/85/Let-s-Learn-Ruby-Basic-85-320.jpg)
![Let’s Learn Ruby
Exercise
please covert a given array [1, 2, 3, 4, 5] to
[1, 3, 5, 7, 9] with Array#map method.](https://image.slidesharecdn.com/letslearnruby-131230165323-phpapp01/85/Let-s-Learn-Ruby-Basic-86-320.jpg)
![Let’s Learn Ruby
my_square = Proc.new { | x | x ** 2 }
!
# how to call a proc
puts my_square.call(10)
puts my_square[10]
puts my_square.(10)
puts my_square === 10
#
#
#
#
100
100
100
100](https://image.slidesharecdn.com/letslearnruby-131230165323-phpapp01/85/Let-s-Learn-Ruby-Basic-107-320.jpg)
![Let’s Learn Ruby
my_lambda = lambda { | x | x ** 2 }
!
# new style in 1.9
my_lambda = -> x { x ** 2 }
!
# how to call a lambda?
puts my_lambda.call(10)
puts my_lambda[10]
puts my_lambda.(10)
puts my_lambda === 10
#
#
#
#
100
100
100
100](https://image.slidesharecdn.com/letslearnruby-131230165323-phpapp01/85/Let-s-Learn-Ruby-Basic-109-320.jpg)
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Let's Learn Ruby - Basic
- 1. Let’s Learn Ruby - Basic
- 3. Ruby Tuesday photo by othree https://www.facebook.com/groups/142197385837507/
- 8. all tickets sold out in 4 mins
- 9. Let’s Learn Ruby What I want?
- 10. Let’s Learn Ruby Problem Solving
- 11. Let’s Learn Ruby Active Ecosystem
- 13. Let’s Learn Ruby open source projects on Github
- 15. Let’s Learn Ruby まつもと ゆきひろ (Matz)
- 16. Let’s Learn Ruby
- 17. Let’s Learn Ruby first released at 1995
- 18. Let’s Learn Ruby 2.0 released at 2013
- 19. Let’s Learn Ruby 2.1 released at 2013.12
- 20. Let’s Learn Ruby Why Ruby? free, open source, easy to learn
- 21. Let’s Learn Ruby Ruby != Rails
- 22. Let’s Learn Ruby Happy, and Fun
- 23. Let’s Learn Ruby Rubies CRuby(MRI), REE, mRuby, MacRuby, JRuby, IronRuby, Rubinius..etc
- 24. Let’s Learn Ruby Version 1.8, 1.9, 2.0, 2.1
- 25. Let’s Learn Ruby Ruby 1.8 has no future
- 26. Let’s Learn Ruby RVM Ruby Version Manager https://rvm.io/
- 27. Let’s Learn Ruby Editors Vim, Emacs, Sublime Text... etc
- 28. Let’s Learn Ruby coding style https://github.com/styleguide/ruby
- 29. Let’s Learn Ruby But Ruby is Slow..?
- 30. Let’s Learn Ruby What can Ruby do?
- 31. Let’s Learn Ruby Rake Make, but Ruby version. Rack http://rake.rubyforge.org/
- 32. Let’s Learn Ruby Rack it’s a specification (and implementation) of a minimal abstract Ruby API that models HTTP. such as Sinatra, Ruby on Rails Rack http://rack.rubyforge.org/ Sinatra http://www.sinatrarb.com Ruby on Rails http://rubyonrails.org/
- 33. Let’s Learn Ruby developing MacOS and iOS app
- 34. Let’s Learn Ruby drawing, image processing, music..
- 35. Let’s Learn Ruby Install Ruby now!
- 37. Let’s Learn Ruby Interactive Ruby, irb
- 39. Let’s Learn Ruby gem install PACKAGE_NAME
- 40. Let’s Learn Ruby gem env
- 41. Let’s Learn Ruby gem list
- 42. Let’s Learn Ruby Variables and Constants
- 43. Let’s Learn Ruby local variable variable
- 44. Let’s Learn Ruby global variable $variable
- 45. Let’s Learn Ruby instance variable @variable
- 46. Let’s Learn Ruby class variable @@variable
- 47. Let’s Learn Ruby virtual variable true, false, self, nil
- 48. Let’s Learn Ruby variable assignment a=1 x, y, z = 1, 2, 3
- 49. Let’s Learn Ruby Constant begins with a capital letter, and it can be changed
- 50. Let’s Learn Ruby Reserved word and Keyword
- 51. Let’s Learn Ruby Reserved word and Keyword
- 52. Let’s Learn Ruby Logic and Flow Control
- 53. Let’s Learn Ruby only false and nil are false
- 54. Let’s Learn Ruby true v.s TrueClass false v.s FalseClass nil v.s NilClass
- 56. Let’s Learn Ruby unless = not if
- 57. Let’s Learn Ruby if modifier
- 58. Let’s Learn Ruby case .. when..
- 59. Let’s Learn Ruby BEGIN{} and END{}
- 60. Let’s Learn Ruby a = true ? 'a' : 'b'
- 61. Let’s Learn Ruby a ||= 'a'
- 62. Let’s Learn Ruby Comment # single line
- 63. Let’s Learn Ruby Comment =begin .. =end
- 64. Let’s Learn Ruby Loop and Iteration
- 65. Let’s Learn Ruby for.. in..
- 66. Let’s Learn Ruby while .. end
- 67. Let’s Learn Ruby until .. end
- 68. Let’s Learn Ruby until = not while
- 70. Let’s Learn Ruby upto, downto
- 71. Let’s Learn Ruby each, each_with_index
- 73. Let’s Learn Ruby Fixnum and Bignum
- 74. Let’s Learn Ruby 10 / 3
- 76. Let’s Learn Ruby single and double quotes
- 77. Let’s Learn Ruby %q v.s %Q
- 78. Let’s Learn Ruby "%s" % "eddie"
- 79. Let’s Learn Ruby string interpolation
- 80. Let’s Learn Ruby Exercise please calculate how many “characters” and “words” of a section of a random article with Ruby.
- 81. Let’s Learn Ruby Exercise please convert string “abcdefg” to “gfedcba” without using String#reverse method.
- 83. Let’s Learn Ruby Array.new v.s []
- 85. Let’s Learn Ruby Exercise please sort a given array [1, 3, 4, 1, 7, nil, 7], and remove nil and duplicate number.
- 86. Let’s Learn Ruby Exercise please covert a given array [1, 2, 3, 4, 5] to [1, 3, 5, 7, 9] with Array#map method.
- 87. Let’s Learn Ruby Exercise please draw 5 unique random number between 1 to 52.
- 89. Let’s Learn Ruby Hash.new v.s {}
- 90. Let’s Learn Ruby a = { :name => 'eddie' } a = { name: 'eddie' }
- 92. Let’s Learn Ruby (1..10) v.s (1...10)
- 93. Let’s Learn Ruby Exercise please calculate the sum from 1 to 100 with Range.
- 95. Let’s Learn Ruby def method_name(param) ... end
- 96. Let’s Learn Ruby parentheses can be omitted
- 97. Let’s Learn Ruby ? and !
- 98. Let’s Learn Ruby return value
- 99. Let’s Learn Ruby Singleton Method
- 100. Let’s Learn Ruby class Cat def walk puts "I'm walking" end end ! cat = Cat.new def cat.fly puts "I can fly" end cat.fly
- 101. Let’s Learn Ruby Method Missing
- 102. Let’s Learn Ruby def method_missing(method_name) puts "method: #{method_name} is called!" end ! something_not_exists()
- 103. Let’s Learn Ruby Exception Handling begin .. rescue.. else.. ensure.. end
- 104. Let’s Learn Ruby def open_my_file(file_name) File.open file_name do |f| puts f.read end end begin open_my_file("block_demo.r") rescue => e puts e else puts "it's working good!" ensure puts "this must be executed, no matter what" end
- 107. Let’s Learn Ruby my_square = Proc.new { | x | x ** 2 } ! # how to call a proc puts my_square.call(10) puts my_square[10] puts my_square.(10) puts my_square === 10 # # # # 100 100 100 100
- 108. Let’s Learn Ruby lambda, ->
- 109. Let’s Learn Ruby my_lambda = lambda { | x | x ** 2 } ! # new style in 1.9 my_lambda = -> x { x ** 2 } ! # how to call a lambda? puts my_lambda.call(10) puts my_lambda[10] puts my_lambda.(10) puts my_lambda === 10 # # # # 100 100 100 100
- 110. Let’s Learn Ruby Proc v.s lambda
- 111. Let’s Learn Ruby def proc_test puts "hello" my_proc = Proc.new { return 1 } my_proc.call puts "ruby" end def lambda_test puts "hello" my_lambda = lambda { return 1 } my_lambda.call puts "ruby" end
- 112. Let’s Learn Ruby {} v.s do..end http://blog.eddie.com.tw/2011/06/03/do-end-vs-braces/
- 115. Let’s Learn Ruby everything in Ruby is an Object
- 116. Let’s Learn Ruby object = state+ behavior
- 117. Let’s Learn Ruby root class = Object root class would be BasicObject in Ruby 1.9
- 118. Let’s Learn Ruby class ClassName < ParentClass ... end
- 119. Let’s Learn Ruby Naming Convention
- 122. Let’s Learn Ruby self = current object
- 123. Let’s Learn Ruby instance and class variable
- 124. Let’s Learn Ruby instance and class method
- 125. Let’s Learn Ruby Exercise please create a Dog class and Cat class, which are both inherited from Animal class, and implement “walk” and “eat” methods.
- 126. Let’s Learn Ruby public, protected and private method
- 127. Let’s Learn Ruby getter and setter
- 128. Let’s Learn Ruby attr_reader, attr_writer and attr_accessor
- 129. Let’s Learn Ruby Open Class
- 131. Let’s Learn Ruby module ModuleName ... end
- 132. Let’s Learn Ruby module has no inheritance
- 133. Let’s Learn Ruby module has no instance
- 134. Let’s Learn Ruby Naming Convention
- 135. Let’s Learn Ruby require v.s load
- 137. Let’s Learn Ruby Exercise please create a Bird class, which is also inherited from Animal class, but include a Fly module.
- 139. Let’s Learn Ruby Ruby is single inheritance
- 140. Let’s Learn Ruby Duck Typing
- 141. Let’s Learn Ruby include v.s extend
- 145. Let’s Learn Ruby gem "nokogiri", :git => "git://github.com/ tenderlove/nokogiri.git" gem "secret_gem", :path => "~/my_secret_path"
- 146. Let’s Learn Ruby bundle install
- 147. Let’s Learn Ruby pack your own gem!
- 148. Let’s Learn Ruby 1. bundle gem NEW_NAME 2. gem build NEW_NAME.gemspec 3. gem push NEW_NAME.gem http://guides.rubygems.org/make-your-own-gem/
- 149. Let’s Learn Ruby Exercise please try to create a Gem spec with bundle command, modify, build and push to rubygems.org.
- 151. Let’s Learn Ruby desc "mail sender" task :sendmail do puts "grap mailing list from database..." sleep 3 puts "mail sending..." sleep 3 puts "done!" end
- 152. Let’s Learn Ruby task :goto_toliet do puts "goto toliet" end ! task :open_the_door => :goto_toliet do puts "open door" end
- 153. Let’s Learn Ruby TDD
- 154. Let’s Learn Ruby require “minitest/autorun" ! class TestMyBMI < MiniTest::Unit::TestCase def test_my_calc_bmi_is_ok assert_equal calc_bmi(175, 80), 26.12 end end ! def calc_bmi(height, weight) bmi = ( weight / (height/100.0) ** 2 ).round(2) end
- 155. Let’s Learn Ruby require "minitest/autorun" describe "test my bmi calculator" do it "should calc the correct bmi" do calc_bmi(175, 80).must_equal 26.12 end end def calc_bmi(height, weight) bmi = ( weight / (height/100.0) ** 2 ).round(2) end
- 156. Let’s Learn Ruby Ruby Koans http://rubykoans.com/
- 157. Let’s Learn Ruby Ruby Object Model
- 158. Let’s Learn Ruby At last..
- 159. photo by redjar
- 160. Let’s Learn Ruby pick up one scripting language
- 161. photo by Quality & Style
- 163. Let’s Learn Ruby Ruby is fun!
- 164. Let’s Learn Ruby The only limitation is your imagination.