What are the differences between Map and Set in Java?

What are the differences between Map and Set in Java?

In Java, a Map is a collection of key-value pairs, while a Set is a collection of unique elements without duplicates.

Can you give me examples of when to use each?

Use a Map when you need to associate values with unique keys, like a phone book. Use a Set when you need to store unique items, like a list of unique user IDs.

Are there any performance differences between them?

Yes, Maps generally have faster lookups for values based on keys, while Sets are optimized for checking the existence of elements.

What are the common implementations of Map and Set?

Common implementations of Map include HashMap and TreeMap, while HashSet and TreeSet are common implementations of Set.