Sort Array Reference by Numeric First Element

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

I'm trying to sort my array_ref data structure by the first element which is numeric. I know I'm on the right track but I can't quite get there.

How do I fix the sort part of this algorithm?

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

my $array = [];

push @$array, [ '1', 'one' ];
push @$array, [ '8', 'eight' ];
push @$array, [ '2', 'two' ];
push @$array, [ '100', 'one hundred' ];
push @$array, [ '4', 'four' ];
push @$array, [ '67', 'sixty seven' ];

my $array2 = sort { $@a->[0] <=> $@b->[0] } @$array;

print Dumper \$array2;
[download]

Comment on Sort Array Reference by Numeric First Element Download Code

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Re: Sort Array Reference by Numeric First Element by japhy (Canon) on Jun 11, 2006 at 05:22 UTC
Change `$@a->[0]` to `$a->[0]` or `$$a[0]` (I suggest and prefer the first form). See perlreftut. Jeff `japhy` Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and `perl` hacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart	[reply] [d/l] [select]
Re: Sort Array Reference by Numeric First Element by liverpole (Monsignor) on Jun 11, 2006 at 05:23 UTC
Hi awohld, You're very close. What you want is to remove the '@' signs on the array references, and to put '[ ... ]' around the sort: `my $array2 = [ sort { $a->[0] <=> $b->[0] } @$array ];` [download] That should do what you need! s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/	[reply] [d/l]
Re: Sort Array Reference by Numeric First Element by sh1tn (Priest) on Jun 11, 2006 at 07:56 UTC
In addition - take a look at sort subroutine. Or (from the command line): perldoc -f sort	[reply]
Re: Sort Array Reference by Numeric First Element by planetscape (Chancellor) on Jun 11, 2006 at 20:00 UTC
For future reference (or to help those who come upon this with their own questions), I offer links to some Tutorials: On Sorting: Complex sorting Resorting to Sorting On References: intro to references References quick reference HTH, planetscape	[reply]