Find out length of linked list in node js

Js program for Find out length of linked list. Here problem description and explanation.

// Node JS Program for
// Find the length of linked list 

// Linked list node
class LinkNode
{
	constructor(value)
	{
		this.data = value;
		this.next = null;
	}
}
class SingleLL
{
	constructor()
	{
		this.head = null;
		this.tail = null;
	}
	// Insert new node at the last
	insert(value)
	{
		// Create new node
		var node = new LinkNode(value);
		if (this.head == null)
		{
			this.head = node;
		}
		else
		{
			// Add new node at the end
			this.tail.next = node;
		}
		this.tail = node;
	}
	// Count number of nodes and 
	// returns the number of nodes
	findLength()
	{
		var temp = this.head;
		var count = 0;
		while (temp != null)
		{
			// Visit to next node
			temp = temp.next;
			// Increase the node counter
			count++;
		}
		return count;
	}
	// Display all Linked List elements
	display()
	{
		if (this.head != null)
		{
			process.stdout.write("Linked List Element :");
			var temp = this.head;
			while (temp != null)
			{
				process.stdout.write("  " + temp.data);
				temp = temp.next;
			}
		}
		else
		{
			console.log("Empty Linked list");
		}
	}
}

function main()
{
	var task = new SingleLL();
	task.insert(5);
	task.insert(10);
	task.insert(15);
	task.insert(20);
	task.insert(25);
	task.insert(30);
	task.insert(35);
	task.display();
	console.log("\nLength :  " + task.findLength());
}
// Start program execution
main();

Output

Linked List Element :  5  10  15  20  25  30  35
Length :  7