すべての出会いが美しいとは限らない。すべての別れが悲しいとは言えない。

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【Ruby】new & initialize

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Class

define a class

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class Klass
  def initialize()
  end
end

create instance by new

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class Hello
  def initialize
  end

  def talk
    puts "Hello world"
  end
end

hello = Hello.new
hello.talk
# => Hello world

new & initialize

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class Hello
  @@name = nil

  def initialize(name)
    @@name = name
  end

  def talk
    puts "Hello #{@@name}"
  end
end

hello = Hello.new("jobs")
hello.talk

# => Hello job

Basic Usage of initialize

Do not override the initialize or return in initialize

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class Hello
  def initialize(he)
    @he = he
  end

  def initialize(he,her)
    @he = he
    @her = her
  end

  def hello
    puts "hello, Mt." + @he.to_s + " and Ms." + @her.to_s
  end

end

hello = Hello.new("Kevin", "Jane")
hello.hello
#=>hello, Mt.Kevin and Ms.Jane

How tocallinitialize` method of parent class

Child class may use the super method to class the initialize method of parent class.

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class Human
  def initialize(name)
    @name = name
  end
end

class Woman < Human
  def initialize(name, bag)
    super name
    @bag = bag
  end
  def who?
    puts "She name is " + @name + " having bag of " + @bag
  end
end

w = Woman.new('Kity','Coach')

w.who?
#=> She name is Kity having bag of Coach