Which is better? ArrayList or LinkedList

Question

Do you know which one is better between ArrayList and LinkdedList in terms of performance, speed and capacity?
Which one do you suggest to use ?
Thanks

Answer 1

It depends upon how the list is going to be used. ArrayLists and LinkedLists work differently -- you need to think about how they each store their data.
ArrayLists store their list items in, well, arrays. This makes them very fast at addressing those items by index #. So any implementation that needs a lot of random access to the list, such as sorting, is going to be relatively fast.
The downside of storing the list in an array presents itself when it comes time to add more items to the list. When it runs out of space in the array, it must create a new larger array and copy the items over to it. Also, if you need to insert or remove an item anywhere other than the end of the list, ArrayList must shift the subsequent items in the list by doing an array copy.
This can be a real drag if you're implementing a queue. This is where LinkedList shines. Each item in the list points to the next and previous ones in the list. Inserting, appending or removing list items involves a couple simple assignment statements. No reallocations or large memory copies are involved. Access is easy as long as it is sequential.
Random access in a linked list is problematic however. In order to get to the Nth item in the list, LinkedList must start with the first item in the list and step through the list N-1 times. An order of magnitude slower than using an ArrayList.