What is the difference between Iterator and Enumeration?

The main difference between Iterator and Enumeration is that Iterator is a universal cursor, can be used for iterating any collection object. On the other hand, the Enumeration is used for traversing object of legacy class only. Enumeration object has only read-only access to the elements in the collection.

What is the difference between Iterator and list Iterator?

listIterator(); Differences between Iterator and ListIterator: 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.

Is enumerator fail-safe?

3. Fail-fast or Fail-safe : Enumeration is fail-safe in nature. It does not throw ConcurrentModificationException if Collection is modified during the traversal. It throws ConcurrentModificationException if a Collection is modified while iterating other than its own remove() method.

Why do we use enumeration?

The benefits of using enumerations include: Reduces errors caused by transposing or mistyping numbers. Makes it easy to change values in the future. Makes code easier to read, which means it is less likely that errors will creep into it.

Where will use Iterator and enumeration?

Iterator can be used for the traversal of HashMap, LinkedList, ArrayList, HashSet, TreeMap, TreeSet . Enumeration is a legacy interface which is used for traversing Vector, Hashtable.

Where will use iterator and enumeration?

Can elements of a list be traversed without using iterator?

Iterator vs ListIterator We can use ListIterator to traverse List only, we cannot traverse Set using ListIterator. 2) We can traverse in only forward direction using Iterator.

Why iterator is fail-fast?

Iterator on ArrayList, HashMap classes are some examples of fail-fast Iterator. This is because, they operate on the clone of the collection, not on the original collection and that’s why they are called fail-safe iterators. Iterator on CopyOnWriteArrayList, ConcurrentHashMap classes are examples of fail-safe Iterator.

Is enumeration synchronized in Java?

As @Mike is saying, creation of enum is guaranteed to be thread safe. However, methods that you add to an enum class do not carry any thread safety guarantee. In particular, the method leaveTheBuilding may be executed, concurrently, by multiple threads.

What is an example of enumeration?

An example of enumerate is when you list all of an author’s works one by one. To determine the number of; count. To count or list one by one. For example, an enumerated data type defines a list of all possible values for a variable, and no other value can then be placed into it.

What is difference between enumeration and iterator in Java?

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. On the other hand, the Enumeration is used for traversing object of legacy class only.

What is difference between iterator and for loop?

An Iterator is an Object, which goes through a Collection and you can do something with whatever the Iterator is pointing at. One big advantage is, that you don’t have to know the size of your Collection. A Loop is a construct, that repeats something for a certain amount of times. One big advantage is, that you always know,…

Is iterator a class or interface?

In Java, Iterator is an interface available in Collection framework in java.util package. It is a Java Cursor used to iterate a collection of objects. It is used to traverse a collection object elements one by one. It is available since Java 1.2 Collection Framework. It is applicable for all Collection classes.

What is the role of iterator in collection framework?

Iterators are used in Collection framework in Java to retrieve elements one by one. There are three iterators. It is a interface used to get elements of legacy collections (Vector, Hashtable).