[SOLVED] Problem with Linked List

[sh4dyPT]

Hello, I have problem with LinkedList implementation,

public class MyLinkedList
{
       private static class Node{
		private String line;
		private Node next;

		private Node(String l){
			this.line = l;
		}
	}
	private Node ListHead;
	
	public MyLinkedList(String  l){
		this.ListHead = nnew Node (l); // Insert first item
	}
        public void insertLast(String l){
		Node newItem = new Node(l);
		// and now?
	}
}

How can I insert a newItem on last position of linked list without adding "private Node last;" at class Node?

any help will be appreciated!

[OrangeDog]

search through list until next==null

[sh4dyPT]

search through list until next==null

I have already tried,

while(this.ListHead  != null){
this.ListHead = this.ListHead.next;
}
ListHead = newItem;

After "while", my object ListHead has always null, and every time when I try to add new item no List, I only have present object on that list, previous objects has already gone.

is this correct way to search for null Node?

this.ListHead = this.ListHead.next;

[OrangeDog]

No, you need to use another variable to hold the current node you're looking at. Using the current method you destroy your linked structure as you go.

[sh4dyPT]

No, you need to use another variable to hold the current node you're looking at. Using the current method you destroy your linked structure as you go.

I don't understand how with another variable possible to add newItem to the end of ListHead. Can you provide some example?

[OrangeDog]

Node curr = listHead;
while(curr.next != null) {
    curr = curr.next;
}
// curr is now the last element in the list

[sh4dyPT]

It solved my problem. Can you explain me a difference between (curr.next != null and curr != null) in while condition?
Thank you, I appreciate you help :)

[OrangeDog]

(curr.next != null) checks to see if the next one is null
(curr != null) checks to see if the current one is null

If you keep going until the current one is null, all you end up with is null, which isn't very helpful.