From: Marcin Grzywaczewski <killavus@...>
Date: 2011-09-01T08:20:19+09:00
Subject: Re: how to pass a variable to a method in an existing class?

"self" is a pointer to an actual element. So if you write:
class String
  def convert
    self.upcase
  end
end

It'll be perfectly fine.

Yours
Martin

2011/9/1 yw hi <yw_hi@163.com>:
> Hi,
>
> I am a new ruby user and I want to add a function to an existing class.
> I googled the answer and found part of the solution. All findings on the
> web adding a new method without a variable. In my case I want to use the
> string as a variable. Here is what I want to do:
> class String
>
> def convert(x)
> #code to convert the x
> x.upcase
> end
> end
>
> What I want is in the irb I can use the new method in the way as:
>
> "a".convert
>
> This will convert a to upper case. However, it does not take the "a" as
> the input variable and generating error
> ArgumentError: wrong number of arguments (0 for 1)
>
> How do I acheive what I want?
>
> Thanks
>
> Frank
>
> --
> Posted via http://www.ruby-forum.com/.
>
>