module

module Tool  #这个方法无法直接运行  def show_tip    "this is the tip"  end  #这个方法可以通过Tool.say来运行  def self.say    puts "self.say"  endend
Tool.say
#############在类中调用############
require './Apple5.rb'
新建Apple4.rb,下面是Apple4.rb的内容class Student  include ToolendStudent.new.show_tipclass Teacher  include ToolendTeacher.new.show_tip
运行结果
vagrant@vagrant-Ubuntu-trusty-64:/vagrant/test_PRoject$ ruby Apple4.rbthis is the tipthis is the tip