modCount

JS
Native
1.1
protected var modCount: Int
(JS source) (Native source)

The number of times this list is structurally modified.

A modification is considered to be structural if it changes the list size, or otherwise changes it in a way that iterations in progress may return incorrect results.

This value can be used by iterators returned by iterator and listIterator to provide fail-fast behavoir when a concurrent modification is detected during iteration. ConcurrentModificationException will be thrown in this case.