| Enumeration | Iterator | |
| 1) | It is legacy interface and introduced in 1.0 version. | It is non-legacy and introduced in 1.2 version. |
| 2) | Applicable only for legacy classes and it is not universal cursor. | Applicable for any Collection implemented class object. |
| 3) | While iterating the elements we are not allowed to remove the objects just we can perform only read operation. | While iterating we can perform removal also in addition to read operation. |
| 4) | By using elements() method we can get Enumeration object. | By using iterator() method we can get Iterator object. |
What are limitations of Enumeration?
- While iterating the elements we are not allowed to perform removal operation.
- It is applicable only for legacy classes and it is not a universal cursor.
- It can retrieve the elements only in forward direction.
What is difference between enum and Enumeration?
An enum can be used to define a group of named constants.
It has introduced in 1.5 version
Ex
Class Beer{
KO,KF,RC,FO
}
Enumeration is cursor to retrieve Objects one by one from
Collection objects.
What is difference between Iterator and ListIterator?
- ListIterator is the child interface of the Iterator
- Iterator is the single direction cursor where as ListIterator is bidirectional cursor.
- While iterating the elements by Iterator we can perform only read and remove operations. But by using ListIterator we can perform read,removal, replace and addition of new objects also.
- Iterator is applicable for every Collecton implemented class object but ListIterator is applicable only for List implemented class objects.
- Iterator can be get by using iterator() of Collection interface where as ListIterator can be get by using listIterator() method of List interface
- both are introduced in 1.2 version
What is relation between ListIterator and Iterator?
ListIterator is child interface of Iterator
