Ruby

First Step

Call Ruby command line

irb

Methode

• Define a methode "m"

def m(name = "World")
puts "Hello Mr #{name.capitalize}!"
end

• Execute

m("nicolas")

Hello Mr Nicolas!
=> nil

Class

class Greeter
  def initialize(name = "World")
   @name = name
  end
  def say_hi
    puts "Hi #{@name}!"
  end
  def say_bye
    puts "Bye #{@name}, come back soon."
   end
end

• class define a new class
• @name is a variable d'instance

Object

irb>o = Greeter.new("Nicolas")
=> #<Greeter:0x00000002579a48 @name="Nicolas">

irb>o.say_hi
Hi Nicolas!
=> nil

irb> o.say_bye
Bye Nicolas, come back soon.
=> nil

Methodes of a particular Object

• Current Object and parent

irb>Greeter.instance_methods
=> [:say_hi, :say_bye, :m, :nil?, :===, :=~, :!~, :eql?, :hash, :<=>, :class, :singleton_class, :clone, :dup, :initialize_dup, :initialize_clone, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s, :inspect, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?, :instance_of?, :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?, :respond_to_missing?, :extend, :display, :method, :public_method, :define_singleton_method, :object_id, :to_enum, :enum_for, :==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]

• Current Object only

irb>Greeter.instance_methods(false)
=> [:say_hi, :say_bye]

Validate Object Methode

irb>o.respond_to?("name")
=> false

o.respond_to?("say_hi")
=> true

o.respond_to?("to_s")
=> true