#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my @x=qw/x y z/;
my @y=@x;
$y[1]='u';
print Dumper \@x, \@y;

@x=( map [qw/x y z/], 1..3 );
@y=@x;
$y[1][1]='u';
print Dumper \@x, \@y;

__END__