From: Pit Capitain <pit@...>
Date: 2002-01-24T19:40:05+09:00
Subject: Re: Array.last Weirdness

On 24 Jan 2002, at 19:28, Tobias Reif wrote:

> Yukihiro Matsumoto wrote:
> 
> 
> >   a.[]=(-1,a[-1]+' bar')
> > 
> > in other words
> > 
> >   a[-1] = a[-1] + ' bar'
> 
> 
> Thank you very much. But I still don't understand :|
> 
> While I know why the last two don't work (because there is no #last=
> mehtod), I would expect all of the following to result in the same (or
> I think it would be possible, and great, if they did):
> 
> Without knowing "the internals", they all seem to say the same:
> 
> <last item> = <last item> + <string>
> 
> a[-1]       = a[-1]       + ' bar'
> 
> array.last  = array.last  + ' bar'
> 
> or
> array.last += " world"
> 
> Tobi

Hi Tobi,

if you define the missing "last=" method using the existing "[]=" 
method, you get the desired behaviour:

class Array
  def last=( value )
    self[ -1 ] = value
  end
end

a = [ "works", "now:", "hello" ]
a.last += " world"
p a # => ["works", "now:", "hello world"]

Regards,
Pit