FAQ 4.59 How do I sort a hash (optionally by value instead of key)?
From: PerlFAQ Server (comdog_at_panix.com)
Date: 02/28/05
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Date: Sun, 27 Feb 2005 23:03:01 +0000 (UTC)
This message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
common questions. The core of this message represents an excerpt
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--------------------------------------------------------------------
4.59: How do I sort a hash (optionally by value instead of key)?
Internally, hashes are stored in a way that prevents you from imposing
an order on key-value pairs. Instead, you have to sort a list of the
keys or values:
@keys = sort keys %hash; # sorted by key
@keys = sort {
$hash{$a} cmp $hash{$b}
} keys %hash; # and by value
Here we'll do a reverse numeric sort by value, and if two keys are
identical, sort by length of key, or if that fails, by straight ASCII
comparison of the keys (well, possibly modified by your locale--see
perllocale).
@keys = sort {
$hash{$b} <=> $hash{$a}
||
length($b) <=> length($a)
||
$a cmp $b
} keys %hash;
--------------------------------------------------------------------
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