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 appropriate initial capacity, choosing the right load factor, and avoiding null keys.

Can you explain why the initial capacity is important?

The initial capacity helps to minimize rehashing, which can be costly in terms of performance.

What is the default load factor, and when should I change it?

The default load factor is 0.75. You should consider changing it if you expect a high number of entries to avoid frequent resizing.

Are there any common pitfalls to avoid when using HashMaps?

Yes, common pitfalls include using mutable objects as keys and not synchronizing access in multi-threaded environments.