How can I sort a Perl hash on values and order the keys correspondingly (in two arrays maybe)?

hash, perl, perl-hash, sorting

Solution

First sort the keys by the associated value. Then get the values (e.g. by using a hash slice).

my @keys = sort { $h{$a} <=> $h{$b} } keys(%h);
my @vals = @h{@keys};

Or if you have a hash reference.

my @keys = sort { $h->{$a} <=> $h->{$b} } keys(%$h);
my @vals = @{$h}{@keys};

Problem

In Perl, I want to sort the keys of a hash by value, numerically: ``` { five => 5 ten => 10 one => 1 four => 4 } ``` producing two arrays: ``` (1,4,5,10) and (one, four, five, ten) ``` And then I want to normalize the values array such that the numbers are sequential: ``` (1,2,3,4) ``` How do I do this?

Original source

Related problems