Ruby On Rails 面试题与答案

Question: How can you fire a method when a module is inside a class?

Fire a method inside a class is very simple.

Say you have a module file trig.rb:

module Trig
  PI = 3.141592654
  def Trig.sin(x)
   # ..
  end
  def Trig.cos(x)
   # ..
  end
end

Now you simply import this module inside your class and invoke the method using the �module.method_name� syntax as shown below

require "trig"

class myclass
y = Trig.sin(Trig::PI/4)

This type of invocation ensures that the right module method gets called.