Sorted order insertion in doubly linked list in typescript

Ts program for Sorted order insertion in doubly linked list. Here problem description and explanation.

// TypeScript Program For
// Insert node in sorted order 

// Define class of linked list Node
class LinkNode
{
	public data: number;
	public next: LinkNode;
	public prev: LinkNode;
	constructor(data: number)
	{
		this.data = data;
		this.next = null;
		this.prev = null;
	}
}
class DoublyLinkedList
{
	public head: LinkNode;
	constructor()
	{
		// Set inital value
		this.head = null;
	}
	// Insert Node at sorted way
	public insert(value: number)
	{
		// Create a dynamic node
		var node = new LinkNode(value);
		if (this.head == null)
		{
			// Add first node
			this.head = node;
		}
		else if (this.head.data >= node.data)
		{
			// When need to add node at begining position
			this.head.prev = node;
			node.next = this.head;
			this.head = node;
		}
		else
		{
			var current = this.head;
			// Find position to add new node
			while (current != null && 
                   current.next != null && 
                   current.next.data <= value)
			{
				current = current.next;
			}
			// Insert new node between the nodes
			node.next = current.next;
			if (current.next != null)
			{
				// When next node exists
				current.next.prev = node;
			}
			node.prev = current;
			current.next = node;
		}
	}
	// Display node element of doubly linked list
	public display()
	{
		if (this.head == null)
		{
			console.log("Empty Linked List");
		}
		else
		{
			console.log("Linked List Head to Tail :");
			// Get first node of linked list
			var temp = this.head;
			var last: LinkNode = null;
			// iterate linked list 
			while (temp != null)
			{
				// Display node value
				console.log("  " + temp.data);
				last = temp;
				// Visit to next node
				temp = temp.next;
			}
			console.log("\nLinked List Tail to Head :");
			// Get last node of linked list
			temp = last;
			// iterate linked list 
			while (temp != null)
			{
				// Display node value
				console.log("  " + temp.data);
				// Visit to prev node
				temp = temp.prev;
			}
		}
	}
	public static main(args: string[])
	{
		var dll = new DoublyLinkedList();
		// Insert following linked list nodes
		dll.insert(5);
		dll.insert(3);
		dll.insert(11);
		dll.insert(4);
		dll.insert(6);
		dll.insert(1);
		dll.insert(8);
		dll.insert(12);
		dll.display();
	}
}
DoublyLinkedList.main([]);
/*
 file : code.ts
 tsc --target es6 code.ts
 node code.js
 */

Output

Linked List Head to Tail :
  1
  3
  4
  5
  6
  8
  11
  12

Linked List Tail to Head :
  12
  11
  8
  6
  5
  4
  3
  1