Find length of circular linked list in typescript

Ts program for Find length of circular linked list . Here problem description and other solutions.

// TypeScript program for
// Count number of nodes in circular linked list 

// Define class of linked list Node
class LinkNode
{
	public data: number;
	public next: LinkNode;
	constructor(data: number, first: LinkNode)
	{
		this.data = data;
		this.next = first;
	}
}
class CircularLinkedList
{
	public head: LinkNode;
	// Class constructor
	constructor()
	{
		this.head = null;
	}
	// Insert node at end of circular linked list
	public insert(value: number)
	{
		// Create a new node
		var node = new LinkNode(value, this.head);
		if (this.head == null)
		{
			// First node of linked list
			this.head = node;
			node.next = this.head;
		}
		else
		{
			var temp = this.head;
			// Find the last node
			while (temp.next != this.head)
			{
				// Visit to next node
				temp = temp.next;
			}
			// Add new node at the last 
			temp.next = node;
		}
	}
	public number countNode()
	{
		if (this.head == null)
		{
			return 0;
		}
		// Start with second node
		var temp = this.head.next;
		// This is used to count linked node
		var count = 1;
		// iterate circular linked list
		while (temp != this.head)
		{
			count += 1;
			// Visit to next node
			temp = temp.next;
		}
		return count;
	}
	public static main(args: string[])
	{
		var cll = new CircularLinkedList();
		// Add nodes
		cll.insert(1);
		cll.insert(3);
		cll.insert(5);
		cll.insert(7);
		cll.insert(9);
		cll.insert(11);
		// Display result
		console.log(cll.countNode());
	}
}
CircularLinkedList.main([]);
/*
 file : code.ts
 tsc --target es6 code.ts
 node code.js
 */

Output

6