From: Ron Green <rongreen1@...>
Date: 2007-09-10T04:23:43+09:00
Subject: Re: Hash

Peter Cooper wrote:
> On 9/9/07, Ron Green <rongreen1@mac.com> wrote:
>>
>> Marcel Molina Jr. wrote:
>> > It should be noted though that String#hash isn't garaunteed to be
>> > unique.
>>
>> Then,again I ask, what is it good for?
> 
> 
> It's still useful as a hash. Marcel wasn't wrong, but *no* fixed size 
> hash
> is "guaranteed" to be unique as that's absolutely impossible, per the
> pigeonhole principle 
> (http://en.wikipedia.org/wiki/Pigeonhole_principle).
> String#hash's hash is of a far lower "quality" than that offered by, 
> say,
> SHA-1 or SHA-2.
> 
> Regards,
> Peter Cooper
> http://www.rubyinside.com/

Peter,
If Its not guaranteed to be unique, then it can't be used for identity.
Can you give me an example of how i would use string.hash?
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