Find middle node of linked list

class Node {
    constructor(value){
        this.value = value;
        this.next = null;
    }
}
 
class LinkedList {
    constructor(value) {
        const newNode = new Node(value);
        this.head = newNode;
        this.tail = this.head;
    }

    printList() {
        let temp = this.head;
        while (temp !== null) {
            console.log(temp.value);
            temp = temp.next;
        }
    }

    getHead() {
        if (this.head === null) {
            console.log("Head: null");
        } else {
            console.log("Head: " + this.head.value);
        }
    }

    getTail() {
        if (this.tail === null) {
            console.log("Tail: null");
        } else {
            console.log("Tail: " + this.tail.value);
        }
    }

    makeEmpty() {
        this.head = null;
        this.tail = null;
        this.length = 0;
    }
 
    push(value) {
        const newNode = new Node(value);
        if (!this.head) {
            this.head = newNode;
            this.tail = newNode;
        } else {
            this.tail.next = newNode;
            this.tail = newNode;
        }
    }
    
    findMiddleNode(){
        // if(!this.head) return undefined;
        // let count = 1;
        // let temp = this.head;
        // while(temp.next){
        //     ++count;
        //     temp = temp.next;
        // }
        // count = Math.floor(count/2)+1;
        // for(let i=0;i<count;i++){
        //     temp = this.head;
        //     this.head = this.head.next;
        // }
        // return temp;
        
        //tortoise & hare approach
        let slow = this.head;
        let fast = this.head;
        while (fast !== null && fast.next !== null) {
            slow = slow.next;
            fast = fast.next.next;
        }
        return slow;
    }

}



let myLinkedList = new LinkedList(1);
myLinkedList.push(2);
myLinkedList.push(3);
myLinkedList.push(4);
myLinkedList.push(5);

console.log("Original list:");
myLinkedList.printList();

const middleNode = myLinkedList.findMiddleNode();
console.log(`\nMiddle node value: ${middleNode.value}`);

// Create a new list with an even number of elements
let myLinkedList2 = new LinkedList(1);
myLinkedList2.push(2);
myLinkedList2.push(3);
myLinkedList2.push(4);
myLinkedList2.push(5);
myLinkedList2.push(6);

console.log("\nOriginal list 2:");
myLinkedList2.printList();

const middleNode2 = myLinkedList2.findMiddleNode();
console.log(`\nMiddle node value of list 2: ${middleNode2.value}`);


/*
    EXPECTED OUTPUT:
    ----------------
    Original list:
    1
    2
    3
    4
    5
    Middle node value: 3
    Original list 2:
    1
    2
    3
    4
    5
    6
    Middle node value of list 2: 4
*/