How can I iterate through nested arrays?

Question

I have created an array as follows

while (defined ($line = ``))

        {
        chomp ($line);
        push @stack,($line);
        }
         


        

Answer 1

#!/usr/bin/perl

use strict;
use warnings;
open IN, "< read.txt" or
    die "Can't read in 'read.txt'!";

my $content = join '', ;

while ($content =~ m`(\d+)`g) {
    print "$1\n";
}