Linked List

import java.util.*;
import java.util.Scanner;
class linklist
{
public static void main(String[] args)
{
LinkedList<Integer> ll=new LinkedList<Integer>();
int ch;
for(;;)
{
System.out.println("1:Append \n 2:Add At First \n 3:Add At Last \n 4:Add At Location \n5:Remove Location \n 6:Remove First \n 7:Remove Last \n 8: Display \n 9:Exit\n");
System.out.println("Enter the choice:");
Scanner in=new Scanner(System.in);
ch=in.nextInt();
switch(ch)
{
case 1:     System.out.println("Enter The Item:");
            int a=in.nextInt();
            ll.add(a);
            break;
case 2:     System.out.println("Enter The Item:");
            a=in.nextInt();
            ll.addFirst(a);
            break;
case 3:     System.out.println("Enter  The Item:");
            a=in.nextInt();
            ll.addLast(a);
            break;
case 4:     System.out.println("Enter the location:");
            int b=in.nextInt();
            System.out.println("Enter  The Item:");
            a=in.nextInt();
            ll.add(b,a);
            break;
case 5:     System.out.println("Enter The location to delete:");
            a=in.nextInt();
            ll.remove(a);
            break;
case 6:     ll.removeFirst();
            break;
case 7:     ll.removeLast();
            break;
case 8:    System.out.println("ELEMENTS ARE:"+ll);
           System.out.println("size of linklist="+ll.size());
           System.out.print("Reverse Data :[ ");
           for(int i=ll.size(); i>0;i--)
             {
             int x=ll.get(i-1);
             System.out.print(+x+" ");
            }
            System.out.print("]\n");
             break;
case 9:   System.exit(0);
default:
              System.out.println("invalid choice:");
             
         }
     }
   }
}