insert.java

public class LinkedList {
    Node headNode;

    /*
    * insert
    * */
    public void insert(int value){
        Node newNode=new Node();
        newNode.value=value;
        /*
        * if we insert the value that will be the end of the linkedList
        * that's why next node is null in the single linkedList
        * */
        newNode.nextNode=null;

        /*
        * headNode!=null means, it's already created
        * */
        if(headNode!=null){
            /*
            * 1. assign the headNode(First Node) to a Node Reference(here n is the object reference)
            * 2. then run the while loop until get the nextNode becomes null
            * --> if it's becomes null, that's the before last node,
            * 3. then nextNode must be null, because it's a last element
            * 4. then assign the created above newNode as the nextNode for the last available node- n.nextNode=newNode;
            * */
            //1
            Node n=headNode;

            //2
            while (n.nextNode!=null){
                n=n.nextNode;
            }
            //3
            n.nextNode=newNode;

            /*
            * if the headNode is null which is means that's the new Node in the LinkedList
            * */
        }else {
            headNode=newNode;
        }
    }
}