ruby 没有让我感到困惑

Question

我从昨天开始学习 Ruby。下面是我的疑惑：

class MegaGreeter
      attr_accessor :names

      def intialize(names="World!")
        @names = names
      end

      def say_test
        if @names.nil?
          puts "nil test..."
        end
      end  

    end


    megaGreeter = MegaGreeter.new
    megaGreeter.say_test // Here showing ouput as "nil test..." 

起初我只是assuming 'nil' almost like 'null' in java。但在上述情况下我的假设似乎是错误的。

我不明白为什么在上面 if @names.nil returning as TRUE?, 既然 @names will have a value "World!" 那么，@names 如何被认为是 null?

我已经搜索过关于“nil”的内容，但我确实没有弄清楚。

Answer 1

你打错了。 #intialize 应该是 initialize.

看，

class MegaGreeter
  attr_accessor :names

  def initialize(names = "World!")
    @names = names
  end

  def say_test
    if @names.nil?
      puts "nil test..."
    else
      puts "@names is not holding nil"
    end
  end  
end

megaGreeter = MegaGreeter.new
megaGreeter.say_test # => @names is not holding nil
megaGreeter = MegaGreeter.new(nil)
megaGreeter.say_test # => nil test...