Check linked list is circular or not in typescript

Ts program for Check linked list is circular or not . Here problem description and other solutions.

// TypeScript Program for
// Check linked list is circular or not

// Define class of linked list Node
class LinkNode
{
	public data: number;
	public next: LinkNode;
	constructor(data: number)
	{
		this.data = data;
		this.next = null;
	}
}
class LinkedList
{
	public head: LinkNode;
	// Class constructor
	constructor()
	{
		this.head = null;
	}
	// Check circular linked list or not
	// Note that this function is not capable to detect loop
	public boolean isCircular()
	{
		if (this.head == null)
		{
			// Case when linked list is empty
			return false;
		}
		else
		{
			var temp = this.head;
			while (temp != null)
			{
				// Visit to next node
				temp = temp.next;
				if (temp == this.head)
				{
					// When detecting circular node
					return true;
				}
			}
			// When not circular linked list
			return false;
		}
	}
	public static main(args: string[])
	{
		var ll = new LinkedList();
		// insert element of linked list
		ll.head = new LinkNode(1);
		ll.head.next = new LinkNode(2);
		ll.head.next.next = new LinkNode(3);
		ll.head.next.next.next = new LinkNode(4);
		ll.head.next.next.next.next = new LinkNode(5);
		if (ll.isCircular())
		{
			console.log("Yes");
		}
		else
		{
			console.log("No");
		}
		// Connect last node to head
		ll.head.next.next.next.next.next = ll.head;
		if (ll.isCircular())
		{
			console.log("Yes");
		}
		else
		{
			console.log("No");
		}
	}
}
LinkedList.main([]);
/*
 file : code.ts
 tsc --target es6 code.ts
 node code.js
 */

Output

No
Yes