What are the differences between List, Set, and Map in Java?

What are the differences between List, Set, and Map in Java?

In Java, List, Set, and Map are part of the Collections Framework. A List allows duplicate elements and maintains order, while a Set does not allow duplicates and does not guarantee order. A Map stores key-value pairs, where each key is unique.

Can you give examples of when to use each type?

Sure! Use a List when you need to maintain the order of elements, like a playlist. Use a Set when you want to ensure uniqueness, like a collection of user IDs. Use a Map when you need to associate keys with values, like a phone book.

What are the performance differences between them?

Lists generally have O(1) access time but O(n) for search. Sets have O(1) for add and remove operations, while Maps have O(1) for get and put operations, depending on the implementation.

Are there any specific implementations I should know about?

Yes! For Lists, you can use ArrayList or LinkedList. For Sets, HashSet and TreeSet are common. For Maps, HashMap and TreeMap are widely used.