use strict;
use warnings;

my (@a1, @a2, %HoA, @AoA);

@a1 = (1,2,3);
@a2 = (2,3,4);

%HoA = (
    'a1' => \@a1,
    'a2' => \@a2
);

print "$_ : @{$HoA{$_}}\n" for keys %HoA;

@AoA = (
    ['a1', \@a1],
    ['a2', \@a2]
);

print "$_->[0] : @{$_->[1]}\n" for @AoA;

@AoA = (
    [@a1, 'a1'],
    [@a2, 'a2']
);

print pop(@$_) . " : @$_\n" for @AoA;