From: Justin Collins <justincollins@...>
Date: 2010-03-27T05:34:52+09:00
Subject: Re: Creating a gsub! method for Arrays

Derek Cannon wrote:
> Derek Cannon wrote:
>   
>> class Array
>>   def gsub!(pattern, replacement)
>>     each { |x|
>>       x.gsub!(pattern, replacement)
>>       }
>>   end
>> end
>>     
>
> Just out of curiosity, does anyone know how Ruby knows what "each" is 
> referring to in this case? It works as intended -- I'm just curious as 
> to HOW.
>   

If I understand your question correctly, "each" is being called on self, 
which will be an instance of Array. "each" is already defined for Array, 
and "gsub!" is just being added to the class.

In the example below, you expect meth2 to be able to call meth1. It is 
analogous to the above.

class A
  def meth1
     puts "hi"
  end

  def meth2
    meth1
  end
end

A.new.meth2


-Justin