Circular queue by using linked list in JavaScript.

CircularQueue.js

class Node {
    constructor(val) {
        this.data = val;
        this.next = null;
    }
}
class CircularQueue {
    constructor() {
        this.front = null;
        this.enqueue = (val) => {
            let newnode = new Node(val);
            if (!this.front)
                this.front = newnode;
            else
                this.rear.next = newnode;
            this.rear = newnode;
            this.rear.next = this.front;
        }
        this.dequeue = () => {
            if (!this.front)
                console.log("Queue is empty!");
            else {
                this.front = this.front.next;
                this.rear.next = this.front;
            }
        }
        this.display = () => {
            let curr = this.front;
            do {
                console.log(curr.data);
                curr = curr.next;
            } while (curr != this.front);
        }
    }
}
const cq = new CircularQueue();
cq.enqueue(10);
cq.enqueue(20);
cq.enqueue(30);
cq.display();
cq.dequeue();
cq.display();
cq.enqueue(40);
cq.display();