Question

I like to turn an array into a hash. However, the values are of unequal length for each key.

Lets say I have

my @array = qw( A 0 B 1 2 3 4 c 5 d 6 7);

Now I like to use the letters as keys and for each such letter/key the following number(s) as their values. So @array should be transformed into %hash as follows

my %hash = ( A => [0],
             B => [1, 2, 3, 4],
             c => [5],
             d => [6, 7]
    );

The difficulty for me is the unequal length of each keys’ value.

Answer 1

Here is a way to do it:

#!/usr/local/bin/perl 
use Data::Dump qw(dump);
use strict;
use warnings;

my @array = qw( A 0 B 1 2 3 4 c 5 d 6 7);
my %hash;
my $key;
foreach (@array) {
    if (/^\D+$/) {
        $key = $_;
        $hash{$key} = [];
    } else {
        push @{$hash{$key}}, $_;
    }
}
dump %hash;

Output:

("A", [0], "c", [5], "d", [6, 7], "B", [1 .. 4])