Demonstration of perl array memory usage

array-mem.pl

#!/usr/bin/perl
use warnings;
use strict;

use Devel::Size qw/size total_size/;
use constant N => 1_000_000;

fillerup: {
    my $x = [2 .. N];
    print size($x) . " " . total_size($x) . "\n";
}

slide_along: {
    my $x = [1];
    for (2 .. N) {
        push @$x, $_;
        shift @$x;
    }
    print size($x) . " " . total_size($x) . "\n";
}

start_empty: {
    my $x = [];
    for (2 .. N) {
        push @$x, $_;
        shift @$x;
    }
    print size($x) . " " . total_size($x) . "\n";
}