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Re: LinkedHashMap - get latest key?

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From Jeff Higgins <jeff@invalid.invalid>
Newsgroups comp.lang.java.programmer
Subject Re: LinkedHashMap - get latest key?
Date Wed, 02 Apr 2014 12:06:24 -0400
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On 04/02/2014 10:44 AM, Andreas Leitgeb wrote:
> Given a LinkedHashMap instance, what would be a
> reasonable way to obtain the latest added key?
>
> The specific definition of "reasonable" being:
>   - no separate keeping track of key-sequence
>   - it should be a O(1) operation, and not
>      have to iterate all keys.
>
> Unlike TreeMap, the LinkedHashMap doesn't implement
> NavigableMap.
>
> If nothing else helps, I'll need to switch to a LinkedList,
> and thereby sell the "O(1)" of searching for an Object (by
> key) in exchange for a "O(1)" of obtaining the last Object.
>
> It just seems odd to me, that a LinkedHashMap doesn't
> have such a nobrainer getter, or, that a LinkedHashMap
> isn't also a NavigableMap with the natural ordering
> induced by position.
>
?
Collections.max(myMap.entrySet())

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Thread

LinkedHashMap - get latest key? Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-04-02 14:44 +0000
  Re: LinkedHashMap - get latest key? Jeff Higgins <jeff@invalid.invalid> - 2014-04-02 12:06 -0400
    Re: LinkedHashMap - get latest key? Jeff Higgins <jeff@invalid.invalid> - 2014-04-02 12:44 -0400
      Re: LinkedHashMap - get latest key? Jeff Higgins <jeff@invalid.invalid> - 2014-04-02 13:13 -0400
        Re: LinkedHashMap - get latest key? Jeff Higgins <jeff@invalid.invalid> - 2014-04-02 13:19 -0400
          Re: LinkedHashMap - get latest key? Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-04-02 21:58 +0000
  Re: LinkedHashMap - get latest key? Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2014-04-16 21:33 -0700
  Re: LinkedHashMap - get latest key? leif.roar@invalid.com (Leif Roar Moldskred) - 2014-04-17 03:32 -0500
    Re: LinkedHashMap - get latest key? Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-04-19 12:51 +0000
      Re: LinkedHashMap - get latest key? v_borchert@despammed.com (Volker Borchert) - 2014-04-21 20:38 +0000
        Re: LinkedHashMap - get latest key? Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-04-25 09:18 +0000

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