What are the differences between Set and List in Java?

What are the main differences between Set and List in Java?

The main differences are that Set does not allow duplicates, while List does. Also, Set is unordered, whereas List maintains order.

Can you give me examples of when to use each?

Use a List when you need to maintain the order of elements or allow duplicates, like a shopping list. Use a Set when you want to ensure uniqueness, like a collection of unique user IDs.

What are the performance implications of using one over the other?

Sets generally have faster lookups for existence checks due to their underlying hash table implementation, while Lists can be slower for such operations but are better for indexed access.

Are there different types of Sets and Lists in Java?

Yes, there are different types. For Sets, you have HashSet, LinkedHashSet, and TreeSet. For Lists, you have ArrayList and LinkedList, each with its own characteristics.