insert node at beginning of circular linked list in swift

Swift program for insert node at beginning of circular linked list. Here problem description and explanation.

import Foundation
// Swift 4 Program 
// Insert node at beginning of circular linked list

// Define class of linked list Node
class LinkNode
{
	var data: Int;
	var next: LinkNode? ;
	init(_ data: Int, _ first: LinkNode? )
	{
		self.data = data;
		self.next = first;
	}
}
class CircularLinkedList
{
	var head: LinkNode? ;
	// Class constructors
	init()
	{
		self.head = nil;
	}
	// Insert node at begining of circular linked list
	func insert(_ value: Int)
	{
		// Create a node
		let node: LinkNode? = LinkNode(value, self.head);
		if (self.head == nil)
		{
			// First node of linked list
			self.head = node;
			node!.next = self.head;
		}
		else
		{
			var temp: LinkNode? = self.head;
			// Find the last node
			while (!(temp!.next === self.head))
			{
				// Visit to next node
				temp = temp!.next;
			}
			// Add node
			temp!.next = node;
			// make new head node
			self.head = node;
		}
	}
	// Display node element of circular linked list
	func display()
	{
		if (self.head == nil)
		{
			print("Empty Linked List");
		}
		else
		{
			print("Linked List Element : ");
			// Get first node
			var temp: LinkNode? = self.head;
			// iterate linked list
			while (temp  != nil)
			{
				// Display node
				print(temp!.data, terminator: "  ");
				// Visit to next node
				temp = temp!.next;
				if (temp === self.head)
				{
					// Stop iteration
					return;
				}
			}
		}
	}
	static func main(_ args: [String])
	{
		let task: CircularLinkedList? = CircularLinkedList();
		// Add following linked list nodes
		task!.insert(8);
		task!.insert(7);
		task!.insert(6);
		task!.insert(5);
		task!.insert(4);
		task!.insert(3);
		task!.insert(2);
		task!.insert(1);
		// Display node
		task!.display();
	}
}
CircularLinkedList.main([String]());

Output

Linked List Element :
1  2  3  4  5  6  7  8


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