What is the difference between Iterator and ListIterator explain with example?

The basic difference between Iterator and ListIterator is that both being cursor, Iterator can traverse elements in a collection only in forward direction. On the other hand, the ListIterator can traverse in both forward and backward directions. But, by using ListIterator you can add elements to a collection.

What is difference between Enumeration and iteration?

Iterator can do modifications (e.g using remove() method it removes the element from the Collection during traversal). Enumeration interface acts as a read only interface, one can not do any modifications to Collection while traversing the elements of the Collection.

Which is faster Enumeration or Iterator?

Enumeration is used to traverse the legacy classes like Vector, Stack and HashTable. Iterator is used to iterate most of the classes in the collection framework like ArrayList, HashSet, HashMap, LinkedList etc. Iterator is fail-fast in nature. Enumeration is not safe and secured due to it’s fail-safe nature.

What is Iterator explain with 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. util package.

What is the advantage of ListIterator over iterator?

Iterator can traverse only in forward direction whereas ListIterator traverses both in forward and backward directions. ListIterator can help to replace an element whereas Iterator cannot. Can traverse elements present in Collection only in the forward direction.

Is enumeration fail fast?

Fail-fast or Fail-safe : Enumeration is fail-safe in nature. Iterator is fail-fast in nature. It throws ConcurrentModificationException if a Collection is modified while iterating other than its own remove() method.

Why iterator is used in Java?

Iterator in Java is used to traverse each and every element in the collection. Using it, traverse, obtain each element or you can even remove. ListIterator extends Iterator to allow bidirectional traversal of a list, and the modification of elements. The iterator() method is provided by every Collection class.

Is iterator an abstract class?

Iterator is an interface. It is not a class. It is used to iterate through each and every element in a list. Iterator is implemented Iterator design pattern.

Can iterator traverse a collection in both directions?

Iterator can traverse only in forward direction whereas ListIterator traverses both in forward and backward directions. ListIterator can help to replace an element whereas Iterator cannot.

When to use listiterator instead of iterator in Java?

ListIterator must be used when we want to enumerate elements of List. This cursor has more functionality (methods) than iterator. ListIterator object can be created by calling listIterator () method present in List interface. Iterator can traverse only in forward direction whereas ListIterator traverses both in forward and backward directions.

What’s the difference between an iterator and an enumeration?

Iterators differ from enumerations by adding an optional remove operation, and having shorter method names. Iterator is the super interface for the Collection interface. The Iterable interface with only one method for returning an Iterator.

What’s the difference between an iterator and a set?

1) Iterator is used for traversing List and Set both. We can use ListIterator to traverse List only, we cannot traverse Set using ListIterator. 2) We can traverse in only forward direction using Iterator. Using ListIterator, we can traverse a List in both the directions (forward and Backward).

Can a iterator replace an element in a list?

ListIterator can replace an element in list collection. The addition of an element is not allowed in case of an iterator as it throws ConcurrentModificationException. ListIterator can add an element in list collection any time easily. Modification of an element is not allowed in case of an iterator as it throws ConcurrentModificationException.