How do I use CopyOnWriteArrayList in Java?

What is a CopyOnWriteArrayList and when should I use it?

A CopyOnWriteArrayList is a thread-safe variant of ArrayList. It's ideal for scenarios where reads vastly outnumber writes.

Can you show me a simple example of how to use it?

Sure! Here's a basic example:

CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
list.add("Hello");
list.add("World");
for (String s : list) {
    System.out.println(s);
}

What are the performance implications of using CopyOnWriteArrayList?

While it provides safe iteration, it can be less efficient for write operations since it creates a new copy of the array on each write.

Are there any alternatives to CopyOnWriteArrayList?

Yes, alternatives include synchronized lists or using other concurrent collections like ConcurrentHashMap, depending on your use case.