my $x = ["hello"];
my $y = ["world"];

print "We have \$x=$x and \$y=$y.\n";
print "The first element of \$x is '$x->[0]'\n";
print "The first element of \$y is '$y->[0]'\n";
print "Now swapping...\n";

$x = $x ^ $y;
$y = $x ^ $y;
$x = $x ^ $y;

print "We have \$x=$x and \$y=$y.\n";
print "The first element of \$x is '$x->[0]'\n";
print "The first element of \$y is '$y->[0]'\n";