Queue in Java Script

class Node {
    constructor(value) {
      this.value = value;
      this.next = null;
    }
}

class Queue {
    constructor() {
      this.first = null;
      this.last = null;
      this.length = 0;
    }

    peek() {
        return this.first;
    }

    enqueue(value) {
        const newNode = new Node(value);
        if (this.first === null) {
            this.first = newNode;
        } else {
            this.last.next = newNode;
        }
        this.last = newNode;
        this.length++;
    }

    dequeue() {
        if (this.first === null) {
            return;
        }
        
        if (this.first === this.last) {
            this.last = null;
        }
        
        this.first = this.first.next;
        this.length--;
    }
}

const myQueue = new Queue();
console.log(myQueue.peek());
myQueue.enqueue("Joy");
myQueue.enqueue("Matt");
myQueue.enqueue("Pavel");
myQueue.enqueue("Samir");
console.log(myQueue.peek());
myQueue.dequeue();
console.log(myQueue.peek());
myQueue.dequeue();
console.log(myQueue.peek());