# Simple arrays:
my @ary1 = ( 'a' .. 'e' );
my @ary2 = ( 0 .. 4 );
my $str = '';
$str .= $_ for @ary1, @ary2;
print $str;

# Array of arrays:
my @AoA = ( [ 'a' .. 'e' ], [ 0 .. 4 ] ); 
my $str2 = '';
$str2 .= @$_ for @AoA;
print $str2;