#Works for all perl versions
join '', @string_arr; #Obviously you can use any string as the first arg of join e.g. "\n"

#Since 5.10(I think?Maybe 5.8)
open STRING_HNDL, ">", \(my $str);
print STRING_HNDL @string_arr;
close STRING_HNDL;
#$str now contains the strings in @string_arr concatenated together

print "@string_arr"; # A space is put in between successive elements of @string_arr