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What is a ListIterator?

What is a ListIterator?

ListIterator is one of the four java cursors. It is a java iterator which is used to traverse all types of lists including ArrayList, Vector, LinkedList, Stack etc. It is available since Java 1.2. It extends the iterator interface.

What are iterators explain with an example?

An Iterator is an object that can be used to loop through collections, like ArrayList and HashSet. It is called an “iterator” because “iterating” is the technical term for looping. To use an Iterator, you must import it from the java.

How do you list iterators?

Methods of ListIterator

  1. void add(E e): Inserts the specified element into the list (optional operation).
  2. boolean hasNext(): Returns true if this list iterator has more elements when traversing the list in the forward direction.

How does ListIterator work?

listIterator(int index) This method used to return a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. The specified index indicates the first element that would be returned by an initial call to next.

What can Iterator and ListIterator work with?

We can use Iterator to traverse Set and List and also Map type of Objects. While a ListIterator can be used to traverse for List-type Objects, but not for Set-type of Objects.

Does LinkedList extend list?

Java LinkedList is an implementation of the List and Deque interfaces. It is one of the frequently used List implementation class. It extends AbstractSequentialList and implements List and Deque interfaces.

Is ListIterator a class or interface?

In Java, ListIterator is an interface in Collection API. It extends Iterator interface. To support Forward and Backward Direction iteration and CRUD operations, it has the following methods. We can use this Iterator for all List implemented classes like ArrayList, CopyOnWriteArrayList, LinkedList, Stack, Vector, etc.

How many types of iterators are there?

Explanation: There are five types of iterators. They are Output, Input, Forward, Random access and Bi-directional.

Is there a current element in the listiterator?

There is no current element in ListIterator. Its cursor always lies between the previous and next elements. The previous () will return to the previous elements and the next () will return to the next element.

What can I use listiterator for in Java?

To support Forward and Backward Direction iteration and CRUD operations, it has the following methods. We can use this Iterator for all List implemented classes like ArrayList, CopyOnWriteArrayList, LinkedList, Stack, Vector, etc.

Where does the cursor go in a listiterator?

There is no current element in ListIterator. Its cursor always lies between the previous and next elements. The previous () will return to the previous elements and the next () will return to the next element. Therefore, for a list of n length, there are n+1 possible cursors.

What kind of traversal does listiterator support?

It supports bi-directional traversal. i.e both forward and backward direction. It supports all the four CRUD operations (Create, Read, Update, Delete) operations. There is no current element in ListIterator.

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