A list is an ordered sequence of values. It may have properties such as being sorted/unsorted, having duplicate values or being unique. The most important part about list structures is that the data has an ordering (which is not the same as being sorted). Ordering simply means that there is an idea that there is a "first" item, a "second" item and so on. Lists typically have a subset of the following operations:
- add an item to the list
- remove an item from the list
- iterate through all items
- and more...
A list may implement only a subset of the above functionality. The description of a list is very general and it can be implemented in a number of different ways.
Two general implementation methods are the array method or the linked list method. We will look at each in turn.
If you used a fixed array you will need to state an initial size. Items are stored in memory consecutively and you can have direct access to any particular item in constant time through the use of its index.