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

“ 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?

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

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/

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!"

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

# 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 

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.

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

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

Ruby Syntax : Loops for in Iterators for i in 1. .. 10 print i , " Hello
" ; 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

for in

Iterators

for i in 1. .. 10

print i , " Hello
" ;

end

projects = [ "Mobracer" , "GodFatherII" , "Tank" , "Madden Quiz" ]

projects .each do |project|

puts project

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

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

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

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

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

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

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

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

TBC...

TBC...