. Java . Java ListIterators

Java ListIterators

java.util.ListIterator

creating a ListIterator

ListIterator listIteratorName = arrayListName.listIterator();
//creating a ListIterator for an ArrayList


ListIterator listIteratorName = linkedListName.listIterator();
//creating a ListIterator for a LinkedList


ListIterator listIteratorName = listName.listIterator();
//creating a ListIterator for a List

ListIterator methods to find out things about the ArrayList

boolean areThereMore = listIteratorName.hasNext();


int whereIsNext = listIteratorName.nextIndex();


boolean wereThereAny = listIteratorName.hasPrevious();


int whereIsPrevious = listIteratorName.previousIndex();

ListIterator methods to retrieve elements

ClassTypeToCastTo nextElement = 
  (ClassTypeToCastTo) listIteratorName.next();


ClassTypeToCastTo previousElement = 
  (ClassTypeToCastTo) listIteratorName.next();

ListIterator methods which alter what is in the underlying ArrayList, LinkedList, or List

arrayListName.add(elementToAdd);
//inserts before what next() would return


arrayListName.set(intOffsetToSetElementAt, objectIn);
//replaces element that was just returned by next() or previous(),
//  can not be called after add.


arrayListName.remove(intOffsetToRemoveElement);
//deletes element that was just returned by next() or previous(), 
//  can not be called after add.

Using a ListIterator to traverse an existing ArrayList

                          
ListIterator listIteratorName = arrayListName.listIterator();


while (listIteratorName.hasNext()) {
    classTypeToCastTo nextElement = 
      (ClassTypeToCastTo) listIteratorName.next();
}

References

online

The Java 2 Platform Specification

Books

Thinking in Java by Bruce Eckel
Core Java (TM) 2 Volume 1 - Fundamentals by Cay Horstmann and Gary Cornell
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