From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-05-16T15:53:31+09:00
Subject: Re: Handling of arrays

On Fri, May 16, 2008 at 8:49 AM, Jesús Gabriel y Galán
<jgabrielygalan@gmail.com> wrote:

> The accumulator then gets updated by
> the result of the block, so the next iteration will be yielded that
> value.

I have realized that this sentence can be confusing: the accumulator doesn't
get updated. The next value for the accumulator will be the result of the block,
not necesarily the same object.

I have read many times that you shouldn't use the same accumulator by
applying destructive methods to it, but I can't remember what the pros and
cons were. So this should not be done:

irb(main):012:0> [1,2,3].inject([]) {|total,x| total << x**2}
=> [1, 4, 9]

Instead you should do this:

irb(main):013:0> [1,2,3].inject([]) {|total,x| total + [x**2]}
=> [1, 4, 9]

Maybe someone can chime in and explain this a little bit better?

Jesus.