From: Eric Hodel <drbrain@...7.net>
Date: 2009-04-04T05:47:15+09:00
Subject: Re: Array#insert with negative index

On Apr 3, 2009, at 12:49, matt neuburg wrote:

> p [1,2,3].insert(-1, "howdy")
> #=> [1, 2, 3, "howdy"]
>
> Docs: "Inserts the given values before the element with the given  
> index
> (which may be negative)."
>
> The element with index -1 is 3, the last item. Before is before. I  
> have
> a feeling, though, that what's meant here is that when the index is
> negative, before means after (perhaps because we're looking at the  
> array
> from the other end, as it were). Is that right?

array: [  1,  2,  3  ]
index:   0   1   2  3
         -4  -3  -2 -1

So -1 is "one before the end", etc.