What are the best practices for using HashMaps in Java?

What are the best practices for using HashMaps in Java?

Some best practices include using the right initial capacity, choosing an appropriate load factor, and avoiding null keys.

Can you explain why the initial capacity is important?

Yes, setting an appropriate initial capacity can reduce the number of rehashing operations, improving performance.

What about the load factor? How does it affect performance?

The load factor determines when to increase the HashMap's capacity. A lower load factor means fewer collisions but uses more memory.

Are there any common pitfalls to avoid when using HashMaps?

Yes, avoid using mutable objects as keys, as they can lead to unpredictable behavior and difficult-to-debug issues.