Comments on: Sorting a HashMap by Value in Java vs Ruby http://tommy.chheng.com/index.php/2009/12/sorting-a-hashmap-by-value-in-java-ruby/ All Things Programming! Fri, 09 Jul 2010 12:52:00 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Jim White http://tommy.chheng.com/index.php/2009/12/sorting-a-hashmap-by-value-in-java-ruby/comment-page-1/#comment-709 Jim White Thu, 11 Feb 2010 00:50:08 +0000 http://tommy.chheng.com/?p=176#comment-709 Groovy is the coolest (i.e., most productive for Java programmers) way to do closures on the JVM. But your example doesn't even need a closure:<br><br>[a:1, b:2, c:1, d:5].keySet().sort()<br>==><br>[a, b, c, d]<br><br>But say you wanted something other than the default order:<br><br>[a:1, b:2, c:1, d:5].keySet().sort { - (it[0] as int) }<br>==><br>[d, c, b, a]<br><br>The dandy thing is those are real Java Collections (Collection, List, Set, Map), so that works with a gigantic base of existing Java libraries. Groovy is the coolest (i.e., most productive for Java programmers) way to do closures on the JVM. But your example doesn't even need a closure:

[a:1, b:2, c:1, d:5].keySet().sort()
==>
[a, b, c, d]

But say you wanted something other than the default order:

[a:1, b:2, c:1, d:5].keySet().sort { – (it[0] as int) }
==>
[d, c, b, a]

The dandy thing is those are real Java Collections (Collection, List, Set, Map), so that works with a gigantic base of existing Java libraries.

]]> By: Christophe Grand http://tommy.chheng.com/index.php/2009/12/sorting-a-hashmap-by-value-in-java-ruby/comment-page-1/#comment-357 Christophe Grand Sun, 13 Dec 2009 09:25:11 +0000 http://tommy.chheng.com/?p=176#comment-357 #(x %) is here equivalent to x, so it's better to write (sort-by x (keys x)) #(x %) is here equivalent to x, so it’s better to write (sort-by x (keys x))

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