Arakaki

def hello(names)
  names.each do |name|
    puts "Hello, #{name.upcase}"
  end
end

rubies = ['MRI','jruby']

hello(rubies)

Arakaki

#定数は大文字アルファベットで始まる
FOO_BAR = 'bar'

#再代入はおk
FOO_BAR = 'bar2'

puts FOO_BAR

Arakaki

n = 2

if n.zero?
  puts "0でした"
elsif n.even?
  puts '偶数'
elsif n.odd?
  puts '奇数ですた'
end

Arakaki

class Ruler
  #rubyではgetterに=をつける習慣がある。というかシンタックスシュガーになっている
  def length=(val)
    @length = val
  end

  def length
    @length
  end
end

Arakaki

class Ruler
  #自動的にgetter setterが実装される
  attr_accessor :length

  def display_length
    puts length
  end
end

ruler = Ruler.new

Arakaki

class Ruler
  attr_accessor :length

  #コンストラクタ
  def initialize(length)
    @length = length
  end
end

ruler = Ruler.new(30)

Arakaki

class Ruler
  attr_accessor :length

  #selfでクラスメソッド
  def self.pair
    [Ruler.new,Ruler.new]
  end
end

puts Ruler.pair

Arakaki

class MyClass
  @@cvar = 'Hello, My class variable!'

  def cvar_in_method
    puts @@cvar
  end

  def self.cvar_in_class_method
    puts @@cvar
  end

Arakaki

class Parent
  def hello
    puts 'Hello,Parent class!'
  end
end

class Child < Parent
  def hi
    puts 'Hello, Child class!'
  end

Arakaki

class Parent
  def hello
    puts 'Hello,Parent class!'
  end
end

class Child < Parent
  def hello
    super
    puts 'Hello,Child class!'