sorting question

thekestrel has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks, I'm trying to sort values of hash (that are numeric) but they seem to be evaluating as strings. i.e.

#!/usr/bin/perl

use strict;

my %hash;
$hash{"cat"} = 2;
$hash{"dog"} = 1;
$hash{"cow"} = 17;

my @arr = sort values %hash;

print "arr : @arr\n";
[download]

which gives...

arr : 1 17 2

How can I make @arr contain a list of numerically sorted values i.e. 1, 2, 17?

Regards Paul

Comment on sorting question Download Code

Replies are listed 'Best First'.
Re: sorting question by holli (Abbot) on Mar 14, 2005 at 19:36 UTC
`my @arr = sort { $a <=> $b } values %hash;` see perldoc -f sort holli, /regexed monk/	[reply] [d/l]
Re^2: sorting question by RazorbladeBidet (Friar) on Mar 14, 2005 at 19:37 UTC
Specifically - "If SUBNAME or BLOCK is omitted, sorts in standard string comparison order." -------------- It's sad that a family can be torn apart by such a such a simple thing as a pack of wild dogs	[reply]
Re: sorting question by Limbic~Region (Chancellor) on Mar 14, 2005 at 19:37 UTC
thekestrel, By default, sort uses the cmp operator. Since you want numerical comparison, you need to use the numerical counterpart <=>(spaceship operator). `print "$_\n" for sort { $a <=> $b } values %hash;` [download] Cheers - L~R	[reply] [d/l]