Re: Sort Map on Value

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 26 Aug 2009 01:44:34 -0400

Message-ID:

<h72i42$s63$2@news.albasani.net>

Andreas Leitgeb wrote:

Lew <noone@lewscanon.com> wrote:

Andreas Leitgeb wrote:

Joshua Cranmer <Pidgeot18@verizon.invalid> wrote:

I believe the TreeMap would be calling the compare function in looking
up a key, so you'd need a different map to back the lookup.

Why that? Isn't the lookup by key still hashCode()/equals()-based?
Maybe indeed I'd need a different map for lookup, but then more likely
because during a put()-operation it will need compare() and by that
time, we might find the TreeMap in an inconsistent state for a get().

<http://java.sun.com/javase/6/docs/api/java/util/TreeMap.html>

... the Map interface is defined in terms of the equals operation,
but a map performs all key comparisons using its compareTo (or
compare) method, ...

And that after I believed to know all the Maps by heart already...

I stand corrected.

I'm pretty sure that the business about using 'compare[To]()' applies only to
SortedMaps.

--
Lew