This seems more like your book is talking about linked lists. A
double linked list class, in this case.
In linked lists you create new elements as needed and link them together using pointers, you don't create a new array and then delete the old one, like you are actually doing.
Your way may work, but it will be very slow if you want to handle a large amount of data.
By the way, learning how to make a linked list class is very funny.
If you are interested, here is some good tutorial:
http://aaroncox.net/tutorials/miscel...nkedLists.html
http://richardbowles.tripod.com/cpp/...t/doublist.htm