Question

我正在学习废墟以及模块和组合。

我尝试了以下法典。废墟档案测试名称。

module Mod1
  def Mod1.sayHello()
    puts "Hello Mod1"
  end

end

module Mod2
  def Mod2.sayHello()
    puts "Hello Mod2"
  end
end


class TestMod
  require  file 
  Mod1.sayHello
end

t = TestMod.new

I am suprised to the output: Hello Mod1 Hello Mod1 (twice)

我没有对此做出解释,一些人能否帮助?

Answer 1

You did not define your initialize method for your class (the constructor). You are simply executing Mod1.sayHello inside the class definition (it is even executed before creating the instance). Try to comment out your t = TestMod.new statement. The output will still stay visible.
Since you include the exact same file, this ends up being executed twice (the file does not get included another time afterwards; ruby prevents this). The class should look like this:

class TestMod
  def initialize
    Mod1.sayHello
  end
end

为什么要把档案列入其中? 这对我来说没有意义。

http://www.un.org。删除了一个错误。

我建议将<代码>Mod1和Mod2在你的模块定义中改为自封。如果改变一段时间,你就必须改变各地的名称。

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