From: SpringFlowers AutumnMoon <summercoolness@...>
Date: 2008-02-03T11:02:25+09:00
Subject: Re: how does sort work?

Chris Sepic wrote:
> I'm confused as to how the sort method works.
> 
> If I have:
> a = [ "d", "a", "e", "c", "b" ]
> 
> I know that
> a.sort {|x,y| x <=> y } (or just .sort)
> = ["a", "b", "c", "d", "e"]
> 
> and
> a.sort {|x,y| y <=> x }
> = ["e", "d", "c", "b", "a"]
> 
> I understand how the <=> operator works, but what exactly is going on in
> the block? What are x and y assigned to?


to understand this, you can think of "sort" taking a function as a 
parameter.  and sort() will pass 2 numbers to this function, and 
rearragne the elements according to the return value of -1, 0, or 1.

that's it.  to understand it fully, you can read about "iterators" in 
Ruby.  where you can take a block as a function, and "yield" arguments 
to this function, and get back a return value.

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