Collections Framework

LinkedList

• The LinkedList class of the Java collections framework provides the functionality of the linked list data structure (doubly linkedlist).
• There are 2 ways to create Vector
• Non-generic
Syntax:
LinkedList LinkedName=new LinkedList();
• Generic
Syntax:
LinkedList<className> ListName=new LinkedList<className>();

• Non-generic LinkedList can store Any type of object like Integer, String, Date…etc
• Generic LinkedList can store only specify the ClassName.

LinkedList

• Each element in a linked list is known as a node. It consists of 3 fields:
• Prev :stores an address of the previous element in the list. It is null for the first element
• Next :stores an address of the next element in the list. It is null for the last element
• Datastores the actual data

LinkedList

• Elements in linked lists are not stored in sequence. Instead, they are scattered and connected through links (Prev and Next).

LinkedList Methods

• void add(value)
• to add an element (node) at the end of the LinkedList.
• void add(index, value)
• to add an element (node) at the end of the LinkedList.
• Object get(index)
• the LinkedList class is used to access an element from the LinkedList.
• Object set(index, value)
• LinkedList class is used to change elements of the LinkedList.
• Object remove(index)
• the LinkedList class is used to remove an element from the LinkedList.

 
import java.util.LinkedList;
class demo
{
  public static void main(String args[])
  {
    LinkedList linkedList=new LinkedList();
    linkedList.add("Amit Jain");
    linkedList.add("Sumit Kumar");
    linkedList.add("Raja Rathi");
    linkedList.add("Gopal Pandey");
    System.out.print(linkedList+"\n");
    linkedList.add(1,"Raj Kumar");
    System.out.print(linkedList);
  }
}

[Amit Jain, Sumit Kumar, Raja Rathi, Gopal Pandey] 
[Amit Jain, Raj Kumar, Sumit Kumar, Raja Rathi, Gopal Pandey]