Re: Glitch in Java Collections (No descendingMap in LinkedHashMap)

From:
Daniel Pitts <newsgroup.nospam@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 05 Oct 2012 15:51:10 -0700
Message-ID:
<zvJbs.1190$nQ6.577@newsfe15.iad>
On 10/5/12 1:04 PM, Lew wrote:

On Friday, October 5, 2012 12:06:18 PM UTC-7, Daniel Pitts wrote:

Iteration is how you reveal the order.


Iteration of what?

Anything that is a view into this map.

Again, my concern is that 'Set' doesn't promise predictable iteration order, in fact,
exactly the opposite. The only iterators available for a 'Map' are through its 'Set'-
returning methods, which result in a collection that promises not to have a predictable
iteration order.

The intent is pretty clear to me. It is predictable if the Set (or
Collection for the values() method) comes from a LinkedHashSet.

So I ask one more time - in what way is that guaranteed iteration order revealed?

By definition of this class, both in documentation and implementation.

I understand that the only way is through those iterators, but the Javadocs have a hole
in them about that.

Perhaps they do, but the intent is more than clear, as is the
implementation. Perhaps the JavaDoc could have been more explicit, but
that isn't the point.

Any iteration over the contents of LinkedHashMap has a guaranteed order.

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