Find second last element in linked list in c++

C++ program for Find second last element in linked list. Here more information.

// Include header file
#include <iostream>
using namespace std;
// C++ program for
// Find the second last node of a linked list

// Node of Linked List
class LinkNode
{
	public: 
    int data;
	LinkNode *next;
	LinkNode(int data)
	{
		// Set node value
		this->data = data;
		this->next = nullptr;
	}
};
class SingleLL
{
	public: LinkNode *head;
	LinkNode *tail;
	SingleLL()
	{
		this->head = nullptr;
		this->tail = nullptr;
	}
	// Add new node at the end of linked list
	void insert(int value)
	{
		// Create a new node
		LinkNode *node = new LinkNode(value);
		if (this->head == nullptr)
		{
			this->head = node;
		}
		else
		{
			this->tail->next = node;
		}
		this->tail = node;
	}
	// Display linked list element
	void display()
	{
		if (this->head == nullptr)
		{
			return;
		}
		LinkNode *temp = this->head;
		// iterating linked list elements
		while (temp != nullptr)
		{
			cout << temp->data << " → ";
			// Visit to next node
			temp = temp->next;
		}
		cout << "null\n";
	}
	//Find the second last node of a linked list
	void secondLast()
	{
		LinkNode *node = this->head;
		if (node == nullptr)
		{
			cout << "Empty linked list";
		}
		else if (node->next == nullptr)
		{
			cout << "Only one node in this linked list";
		}
		else
		{
			// Find second last node
			while (node->next != nullptr && node->next->next != nullptr)
			{
				// Visit to second next node
				node = node->next->next;
			}
			cout << "Second last element is : " << node->data << endl;
		}
	}
};
int main()
{
	SingleLL *sll = new SingleLL();
	// Add linked list node
	sll->insert(6);
	sll->insert(3);
	sll->insert(2);
	sll->insert(7);
	sll->insert(1);
	sll->insert(9);
	cout << "Linked List" << endl;
	// 6 → 3 → 2 → 7 → 1 → 9 → null
	sll->display();
	sll->secondLast();
	return 0;
}

Output

Linked List
6 → 3 → 2 → 7 → 1 → 9 → null
Second last element is : 1