Hi, Derek
I don't think that the problem you have is on *inject*. Rather it is
this:
a) Array has many instance methods; two of them are: first, last
arr = [ 'jules', 'jim', 'catherine' ]
arr.first # => "jules"
arr.last # => "catherine"
And, of course, if you have an array of arrays, and you apply those methods
on each...
but rather than continuing (and ruin the discovery for you), I would let you
apply this on the code that you wrote, and see if you discover it (what you
get is 5 times more valuable than if I continue).
But if still something is not clear, let me know.
Your question was excellent, by the way. I am sure that many will benefit
from them,
Raul
On Sun, Nov 16, 2008 at 11:39 AM, Derek W <[EMAIL PROTECTED]> wrote:
> HI guys,
>
> Sorry to bring up an old topic as I found out about this class just
> recently. While going over exercise 4.4, it took me a while to figure out
> everything that was going on. I DO understand it all now (after some
> research), but was hoping to find out more information about inject which I
> wasn't able to find online.
>
> Here is a sample code I found explaining inject. While I understand the
> usage, I am confused with how this code below works:
>
> hash = [[:first_name, 'Shane'], [:last_name, 'Harvie']].inject({}) do
> |result, element|
> result[element.first] = element.last
> result
> end
>
> From my reading, I understand that inject iterates through each element.
> Now in this above example, you have an array of an array. What I'm confused
> about is why inject grabs the first two elements (:first_name and Shane).
> Maybe I just do not understand correctly the concept of array of arrays?
> Being that there is 4 elements total, I would have thought element would
> only include the symbol :first_name the first time it was run.
>
> Can someone explain this one to me?
>
> >
>
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