#!/usr/bin/perl -wl

    use strict;


    my @a;
    my @b;

    my $a = \@a;
    my $b = \@b;

    print ref $a;
    print ref $b, "\n";

    bless $a;

    print ref $a;
    print ref $b, "\n";


    print 'ARRAY' if UNIVERSAL::isa($a, 'ARRAY');
    print 'ARRAY' if UNIVERSAL::isa($b, 'ARRAY');

    __END__
    Prints:

    ARRAY
    ARRAY

    main
    ARRAY

    ARRAY
    ARRAY