From: Jeremy Bopp <jeremy@...>
Date: 2011-05-27T01:14:59+09:00
Subject: Re: Method that mutates object

On 5/26/2011 11:07, jay s. wrote:
> I understand that using String#replace works for the String class, but 
> what if you were writing a random method for Integer that takes a number 
> and sets it equal to some other number.
> 
> Ex.
> 
> x = 7
> 
> class Integer
>   def crazy
>     ...set x to 5...
>   end
> end
> 
> 
> now when you call x the value is 5

Instances of Integer are immutable, so you can't do that.  The
documentation for Fixnum (a descendant of Integer) mentions this in the
Overview section:

http://rdoc.info/stdlib/core/1.9.2/Fixnum

-Jeremy