From: "Florian Groß" <florgro@...>
Date: 2005-04-10T01:26:15+09:00
Subject: Re: Array#last_index

jzakiya@mail.com wrote:

> array.last returns the value of the last array element.
> 
> In many instances it is necessary to get the index value
> of the last array element. This is necessary in many
> sorting and searching algorithms, especially where the
> arrays are dynamically changing in size. You can do it like:
> 
> class Array
>   def last_index;  self.length - 1 end
> end
> 
> But this is slower than necessary, because array.last
> already computes/knows what the last index value is,
> and thus the mechanism already exists to get this info.
> 
> I would really like to see this method added to class Array.
> It is a nice complement to Array#last, and aides performance.

Can you not just use -1 as the index?