Linked List

class Node
{
int data;
Node next;
Node(int val)            // Constructor to create a node
{
data=val;
next=null;
}
void link(Node n)
{
next=n;
}
}
class LinkList
{
    Node head;
LinkList(Node n)
{
head=n;
}
void print()                  //Method to print the value of list
{
Node nodePtr=head;
System.out.print("[");
while(nodePtr!=null)
{
System.out.print(nodePtr.data+" ");
nodePtr=nodePtr.next;
}
System.out.println("]");
}
void putAtStart(int val)      // Method to add a node at the start Position
{

Node newNode=new Node(val);
newNode.next=head;
head=newNode;

}
 void putAtLast(int val1)     //Method to add a node at the last position  (Problem is here...)
{
    Node nodePtr1=head;
    Node newNode1=new Node(val1);
    newNode1.next=null;
while(nodePtr1!=null)
{
nodePtr1=nodePtr1.next;
}
nodePtr1.next=newNode1;
}
}
public class LinkedList
{
public static void main(String args[])
{
Node n1=new Node(5);
Node n2=new Node(12);
Node n3=new Node(22);
Node n4=new Node(6);
n1.link(n2);
n2.link(n3);
n3.link(n4);
LinkList list1=new LinkList(n1);
list1.print();
System.out.println("Adding some value at the start posision");
list1.putAtStart(25);
list1.putAtStart(99);
list1.print();
System.out.println("Adding some value at the last posision");
list1.putAtLast(57);
list1.putAtLast(64);
list1.print();
}
}