From: "David A. Black" <dblack@...>
Date: 2008-08-25T20:54:56+09:00
Subject: Re: indices of non nil elements in an array

Hi --

On Mon, 25 Aug 2008, Patrick Doyle wrote:

> a = []
> a[10] = "foo"
>
> a.nitems returns a count of the non-nil, items. What is the simplest
> way to return the indices of "a" that are not nil?
>
> I'm sure there is some simple elegant way to do this, but I can't figure it out.

Try this:

(0...a.size).reject {|i| a[i].nil? }

or select for a[i] if you don't mind losing false as well as nil.


David

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