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From: "Arne Vajhøj" <arne.vajhøj@1:261/38.remove-fzq-this>
Subject: Re: hashCode
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Date: Mon, 20 Aug 2012 18:58:36 GMT
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  To: Robert Klemme
From: Arne Vajhoj <arne@vajhoej.dk>

On 8/13/2012 1:17 PM, Robert Klemme wrote:
> On 12.08.2012 22:59, Arne Vajhoj wrote:
>> On 8/12/2012 11:06 AM, Robert Klemme wrote:
>>> The whole idea of hashing is based on the fact that the hash code
>>> _somehow_ represents the item to be hashed.  If all items have the same
>>> constant hash code there is no point in hashing at all.  So while it
>>> does work, it does not work as intended.
>>
>> It disable the entire hashing functionality and a HashMap get
>> characteristics of ArrayList.
>
> An ArrayList allows multiple occurrences of the same instance - and does
> not store key value pairs.  That won't be the case with HashMap as
> equals() (if properly implemented) will prevent that (albeit slowly, or
> more correct: slower than with a proper implementation of hashCode()).
> Also, a HashMap will degenerate more to a LinkedList via the chaining of
> a bucket's entries.

I guess my statement was a bit misleading.

... get O(1) characteristics for getting data similar to various List 
implementation.

Arne

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