LinkedList:

• Like ArrayList, LinkedList is another implementation class of List interface.
• Underlying data structure is the double linked list.
• Duplicates are allowed.
• Insertion order is preserved.
• Null insertion is possible.
• LinkedList implements Serializable and Clonable interface, but not RandomAccess interface.
• If our frequent operation is the insertion and deletion in the middle, then LinkedListis the best choice.
• If our frequent operation is the retrieval operation then LinkedList is the worst choice. Because here retrieval of data items is a time consuming process.
• Usually we can use LinkedList to implement Stacks and Queues to provide support for this requirement. LinkedList class defines following specific methods:

Constructors:

• Creates an empty LinkedList Object.
  LinkedList l=new LinkedList();
• Creates an equivalent LinkedList Object for the given Collection.
  LinkedList l=new LinkedList(Collection c);

Example :LinkedListDemo.java:

Output

[Tapuuu,Mona,Divya,25,null]
Tapuuu
Mona
Divya
25
Null
[Tilan,Tapuuu,Mona,Divya,25,null,Kandhei]
[Tapuuu,Mona,Divya,25]

ArrayList vs. LinkedList:

ArrayList:

• It is the best choice if our frequent operation is retrieval.
• It is the worst choice if our frequent operation is insertion and deletion.
• Underlying data structure for ArrayList is resizable or growable array.
• It implements RandomAccess interface.

LinkedList:

• It is the best choice if our frequent operation is insertion and deletion.
• It is the worst choice if our frequent operation is retrieval operation.
• Underlying data structure is double linked list.
• It does not implement RandomAccess interface.