to its iterator(method)java util iterator objects have "fail-fastfeature that immediately invalidates such an iterator if its underlying collection is modified unexpectedly for exampleif java util linkedlist object has returned five different iterators and one of them modifies lthen the other four all become immediately invalid that isjava allows many list iterators to be traversing linked list at the same timebut if one of them modifies (using an addsetor remove method)then all the other iterators for become invalid likewiseif is modified by one of its own update methodsthen all existing iterators for immediately become invalid the java util list interface and its implementations java provides functionality similar to our array list and node lists adt in the java util list interfacewhich is implemented with an array in java util arraylist and with linked list in java util linkedlist there are some trade-offs between these two implementationswhich we explore in more detail in the next section moreoverjava uses iterators to achieve functionality similar to what our node list adt derives from positions table shows corresponding methods between our (array and nodelist adts and the java util interfaces list and listiterator interfaceswith notes about their implementations in the java util classes arraylist and linkedlist table correspondences between methods in the array list and node list adts and the java util interfaces list and listiterator we use and as abbreviations for java util arraylist and java util linked list (or their running timeslist adt method java util list method listiterator method notes size(size( ( time