Sorting by length in Perl

Question

Anyone have any idea how to sort number by length?

Ex : (11,111,122,12,2,13,21,15,211,22,213,2004)

I wanted the sorted array to be:

Click to copy

11
12
13
15
111
122
2
21
22
213
2004

Answer 1

The desired output seems to indicate you don't just want to sort by the number of digits, but rather first sort by the first digit and then by the length.

The desired output you show omits 211, so I just put it where it belonged according to my understanding.

Click to copy

#!/usr/bin/env perl

use strict;
use warnings;

use Test::More;

my @source = (11, 111, 122, 12, 2, 13, 21, 15, 211, 22, 213, 2004);
my @desired = (11, 12, 13, 15, 111, 122, 2, 21, 22, 211, 213, 2004);

my @sorted =sort {
    substr($a, 0, 1) <=> substr($b, 0, 1) ||
    length($a) <=> length($b) || 
    $a <=> $b # thanks @ikegami
} @source;

is_deeply(\@sorted, \@desired, 'Sorted and desired are the same');