my @array = ( 1 .. 10 );
$array[7] = $array[7] . $array[8];
print "$array[7]\n";
print "$array[8]\n";

##</code><code>##

89
9

##</code><code>##

my @array = ( 1 .. 10 );
$array[7] = $array[7] + $array[8];
print "$array[7]\n";
print "$array[8]\n";

##</code><code>##

17
9