Linked List

What is Linked List?

• The underlying data structure is doubly linked list
• Insertion order is preserved 
• Duplicate objects are allowed
• Heterogeneous objects are allowed
• null insertion is possible
• Linked list implements Serializable and cloneable interfaces but not random access
• A linked list is the best choice if the ever frequent operation is insertion or deletion in the middle
• A linked list is the worst choice if the ever frequent operation is retrieval operation

Constructors::

1) LinkedList l=new LinkedList(); ---->  creates an empty linked object
2) LinkedList l=new LinkedList(Collection c); ----> creates an equivalent linked list object for the given collection.

---> Usually we can use linked lists to develop stacks and queues.To provide support for these requirement linked list class defines the following specific methods::

1. void addFirst(Object o)
2. void addLast(Object o)
3. Object getFirst()
4. Object getLast()
5. Object removeFirst()
6. Object removeLast()

Key Points:

• LinkedList  is the best choice if ever frequent operation is insertion/deletion in the middle
• LinkedList is the worst choice if ever frequent operation is retrieval operation
• In LinkedList, the elements won't be stored in consecutive memory locations and hence retrieval operation will become difficult

Please comment below to feedback or ask questions.