What are hashmap iterators and how do they work?

What are hashmap iterators and how do they work?

Hashmap iterators allow you to traverse the elements in a hashmap. They provide a way to access each key-value pair without needing to know the underlying structure.

Can you explain the difference between keySet() and entrySet() in hashmap iterators?

Sure! keySet() returns a set view of the keys contained in the hashmap, while entrySet() returns a set view of the key-value pairs.

How do I use a hashmap iterator in Java?

In Java, you can use the Iterator interface to iterate over a hashmap. For example, you can get an iterator from the entrySet() and then loop through it.

Are there any performance considerations when using hashmap iterators?

Yes, using iterators is generally efficient, but be cautious when modifying the hashmap during iteration, as it can lead to ConcurrentModificationException.