Ruby Hell Yeah

“ A language that doesn’t affect the way you think about programming is not worth knowing” — Alan Perlis

Ruby? HELL YEAH! htttp://syamantics.com

./toc What is Ruby? Installing Ruby Writing our first Ruby program Ruby v/s PHP Syntax What’s so special about Ruby??

What is Ruby? A dynamic, object-oriented programming language that is way too different than C-type languages. Inspired by LISP, Perl, SmallTalk Simple, elegant, natural syntax Created by Yukihiro Matsumoto, a.k.a. Matz

Installing Ruby Windows http://rubyforge.org/frs/?group_id=167 Ubuntu sudo apt-get install ruby ri irb You can even try out ruby online! http://tryruby.hobix.com/

Our First Ruby Program Open Your Interactive Ruby Shell Open up Command Prompt/Shell/Terminal and type irb , then hit enter. Now enter this, puts "Hello World!"

Our Second Ruby Program # The Greeter class class Greeter def initialize (name = "World" ) @name = name end def say_hi puts "Hi #{ @name } !" end def say_bye puts "Bye #{ @name } , see you next week." end end # Initialize our Greeter g = Greeter.new "Trippert Tech Session“ # Say hi g .say_hi # Say bye g .say_bye

Ruby v/s PHP Well, there are number of differences! Ruby is fully OOP, PHP is not. Ruby has got no primitive type, PHP has. In Ruby, classes are objects, In PHP, classes are classes. PHP function calls are Ruby messages. Ruby uses sigil denotes for variable scoping. Ruby has closures, anonymous functions, PHP does not*. … . And many many many more. There’s a create_function() function in PHP to create anonymous function though 

Ruby Syntax : Branches if-else switch case if xtra_large do_xtra_large elsif large do_large elsif medium do_medium else #small do_small end do_xtra_large if xtra_large ending if

Ruby Syntax : Loops for in Iterators for i in 1. .. 10 print i , " Hello\n" ; end projects = [ "Mobracer" , "GodFatherII" , "Tank" , "Madden Quiz" ] projects .each do |project| puts project end while i = 5 while i > 0 puts i i -= 1 end

Ruby Syntax : Containers Arrays Hashes my_array = Array.new my_array = [] my_array .push "One" my_array .push "Two" my_array = [ "One" , "Two" , "Three" , "Four" , "Five" ] new_array = my_array[ 1. . 3 ] new_array = my_array[ 1 , 3 ] people = { "linus" =>{ "lname" => "Torvalds" , "fname" => "Linus" , "project" => "Linux" }, "matz" =>{ "lname" => "Matsumoto" , "fname" => "Yukihiro" , "project" => "Ruby" }, "DHH" =>{ "lname" => "Hanmer Heinsen" , "fname" => "David" , "project" => "RoR" }, "nate" =>{ "lname" => "Abel" , "fname" => "Nate" , "project" => "CakePHP" } } people .select do |nick, info| puts nick info .select do |key, value| puts key , value end end

Ruby Syntax : Subroutines, Modules Subroutines Modules def doubleMe ( number ) number * 2 end puts doubleMe 3 module MyMath def doubleMe ( number ) number * 2 end end include MyMath puts doubleMe 3 module MyMath TWO = 2 def MyMath .doubleMe( number ) number * TWO end end include MyMath puts MyMath .doubleMe 3 Modules

Ruby Syntax : Classes and Objects Classes & Objects class MyMath def initialize @two = 2 end def doubleMe (number) number * @two end end my_math = MyMath.new puts my_math .doubleMe 4

Ruby Syntax : Inheritance Extending A Class Including Modules class MyParentMath def initialize @two = 2 end def doubleMe (number) number * @two end end class MyChildMath < MyParentMath def quadropoleMe (number) doubleMe (number) * doubleMe(number) end end my_math = MyChildMath.new puts my_math .quadropoleMe 4 module MyMathModule TWO = 2 def doubleMe (number) number * TWO end end class MyChildMath include MyMathModule def quadropoleMe (number) doubleMe (number) * doubleMe(number) end end my_math = MyChildMath.new puts my_math .quadropoleMe 4

Ruby Syntax : Conventions ClassNames method_names and variable_names methods_asking_a_question? slightly_dangerous_methods! @instance_variables $global_variables local_variable SOME_CONSTANTS or OtherConstants

What’s so special about Ruby?? Introspection Close to Natural Language Method Redefinition Mixins Implicit Singleton methods Meta-programming Dynamic typing No Primitives Yield Powerful Fully Object Oriented Flexible Symbols Minimalism DRY method_missing Hooks Anonymous function Modules Multiple Inheritence Blocks Reflection Closures Open objects Classes are objects Dynamic Operator Overloading Open classes Sigil Denotes Eval Simplicity Optional Parentheses Iterators attr_accessor Syntactic Sugar Optional Punctuation Write Less Do More

Ruby Hell Yeah

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Ruby Hell Yeah