From: Quintus <sutniuq@...>
Date: 2011-05-26T05:45:43+09:00
Subject: 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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