What is the main difference between Iterator and ListIterator?

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. Using iterator you can not add any element to a collection.

What is difference between Enumeration and iteration?

1) The main difference between Iterator and Enumeration is removal of the element while traversing the collection. Iterator can remove the element during traversal of collection as it has remove() method.

What is a ListIterator in Java?

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 is the difference between Iterator and enhanced for?

The difference is largely syntactic sugar except that an Iterator can remove items from the Collection it is iterating. Technically, enhanced for loops allow you to loop over anything that’s Iterable, which at a minimum includes both Collections and arrays. Don’t worry about performance differences.

What is the relationship between Iterator and ListIterator interface?

An Iterator is an interface in Java and we can traverse the elements of a list in a forward direction whereas a ListIterator is an interface that extends the Iterator interface and we can traverse the elements in both forward and backward directions.

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.

What’s the difference between Enumeration and Iterator interfaces?

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. Iterator is not a legacy interface.

Why Enumeration is faster than Iterator?

In the example of the micro-benchmark given, the reason the Enumeration is faster than Iterator is because it is tested first. 😉 The longer answer is that the HotSpot compiler optimises a whole method when a loop has iterated 10,000 times.

What is the relationship between iterator and ListIterator interface?

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.

When should I use iterators?

You might want to use an iterator if you are going to add/remove items to the vector while you are iterating over it. If you were using indices you would have to shuffle items up/down in the array to handle the insertions and deletions.

Is enhanced for loop faster?

7 Answers. It’s a bit of an oversimplification to say that the enhanced for loop is more efficient. It can be, but in many cases it’s almost exactly the same as an old-school loop.

How does the Iterator interface work in Java?

Iterator Methods. Description: Returns the next element in the collection.

What is difference iterator and enumeration?

Key Differences Between Iterator and Enumeration in Java The main difference between Iterator and Enumeration is that Iterator is a universal cursor, can be used for iterating any collection object. Enumeration object has only read-only access to the elements in the collection. There are two methods of iterator one to check the status of collection and one to retrieve the elements from the collection.

What is difference between iterator and for loop?

How it works Iterator: Iterator can be used only for Collection. Iterator is an abstract method of an Iterable interface.

What does this Java Iterator do?

Java Iterator. An Iterator is an object that can be used to loop through collections,like ArrayList and HashSet.