What processes occur during the addition of an element to CopyOnWriteArrayList from the perspective of iteration?

CopyOnWriteArrayList is a thread-safe implementation of a list that creates a new copy of the internal array with each modification operation (for example, adding an element).

When adding an element, the following occurs:

1. A new copy of the internal array is created with a size one larger.
2. All old elements are copied into the new copy.
3. The new element is added to the end of the new copy.
4. The reference to the internal array is updated to the new copy.

From an iteration perspective, this means that iterators work with an immutable copy of the array that was current at the time of the iterator's creation. Even if new elements are added to the list, the iterator will continue to traverse the old version of the array without throwing a ConcurrentModificationException.

This ensures safe iteration without locks, but adding elements is resource-intensive due to copying the entire array.