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Re: Method that mutates object

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Am 25.05.2011 21:22, schrieb jason solomon:
> Say we want to write a String method called clear that takes a given
> string and modifies that string to be equal to "".
> 
> Ex.
> 
> str = "string"
> 
> we call str.clear and we get back "", not just "" printed to the screen,
> but the value of str is now "" (mutate the original string).
> 
> 
> I understand that the following code would just print "" to the screen
> but not modify the actual str object.
> 
> class String
>   def clear
>     ""
>   end
> end
> 
> 
> How would you write a method that actually modifies the str object?
> 

Just in addition to what the others said, the method String#clear
already exists.

=================================================
$ ri String#clear
= String#clear

(from ruby core)
-
------------------------------------------------------------------------------
  string.clear    ->  string

-
------------------------------------------------------------------------------

Makes string empty.

       a = "abcde"
       a.clear    #=> ""
=================================================

And does exactly what you want it to.

Vale,
Marvin
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Method that mutates object jason solomon <solomon.jas@gmail.com> - 2011-05-25 14:22 -0500
  Re: Method that mutates object Stefano Crocco <stefano.crocco@alice.it> - 2011-05-25 14:28 -0500
    Re: Method that mutates object jason solomon <solomon.jas@gmail.com> - 2011-05-25 15:52 -0500
  Re: Method that mutates object Adam Prescott <adam@aprescott.com> - 2011-05-25 14:31 -0500
  Re: Method that mutates object Quintus <sutniuq@gmx.net> - 2011-05-25 15:45 -0500
    Re: Method that mutates object jason solomon <solomon.jas@gmail.com> - 2011-05-25 16:03 -0500
  Re: Method that mutates object jason solomon <solomon.jas@gmail.com> - 2011-05-25 15:59 -0500
    Re: Method that mutates object Brian Candler <b.candler@pobox.com> - 2011-05-25 16:20 -0500
  Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-25 16:36 -0500
    Re: Method that mutates object 7stud -- <bbxx789_05ss@yahoo.com> - 2011-05-25 17:00 -0500
  Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-26 08:56 -0500
    Re: Method that mutates object Jeremy Bopp <jeremy@bopp.net> - 2011-05-26 09:43 -0500
      Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-26 10:00 -0500
        Re: Method that mutates object Josh Cheek <josh.cheek@gmail.com> - 2011-05-26 13:12 -0500
  Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-26 10:55 -0500
  Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-26 11:07 -0500
    Re: Method that mutates object Jeremy Bopp <jeremy@bopp.net> - 2011-05-26 11:14 -0500
      Re: Method that mutates object "jay s." <solomon.jas@gmail.com> - 2011-05-26 11:30 -0500
    Re: Method that mutates object Gary Wright <gwtmp01@mac.com> - 2011-05-26 16:34 -0500
      Re: Method that mutates object Adam Prescott <adam@aprescott.com> - 2011-05-27 10:57 -0500
      Re: Method that mutates object Christopher Dicely <cmdicely@gmail.com> - 2011-05-28 13:05 -0500
        Re: Method that mutates object Gary Wright <gwtmp01@mac.com> - 2011-05-28 19:29 -0500
          Re: Method that mutates object Gary Wright <gwtmp01@mac.com> - 2011-05-28 21:06 -0500

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