Java collection insertion: Set vs. List

Question

I\'m thinking about filling a collection with a large amount of unique objects. How is the cost of an insert in a Set (say HashSet) compared to an List (say ArrayList)?

Answer 1

If you're certain your data will be unique, use a List. You can use a Set to enforce this rule.

Sets are faster than Lists if you have a large data set, while the inverse is true for smaller data sets. I haven't personally tested this claim.

Which type of List?
Also, consider which List to use. LinkedLists are faster at adding, removing elements.

ArrayLists are faster at random access (for loops, etc), but this can be worked around using the Iterator of a LinkedList. ArrayLists are are much faster at: list.toArray().