What is a circular queue in JavaScript and how do I implement one?

What is a circular queue in JavaScript and how do I implement one?

A circular queue is a linear data structure that follows the FIFO principle but connects the end back to the front. To implement one in JavaScript, you can use an array and two pointers to track the front and rear of the queue.

Can you show me a simple implementation of a circular queue?

Sure! Here's a basic implementation:

class CircularQueue {
    constructor(size) {
        this.queue = new Array(size);
        this.front = -1;
        this.rear = -1;
        this.size = size;
    }

    enqueue(element) {
        if ((this.rear + 1) % this.size === this.front) {
            console.log('Queue is full');
            return;
        }
        if (this.front === -1) {
            this.front = 0;
        }
        this.rear = (this.rear + 1) % this.size;
        this.queue[this.rear] = element;
    }

    dequeue() {
        if (this.front === -1) {
            console.log('Queue is empty');
            return;
        }
        const element = this.queue[this.front];
        if (this.front === this.rear) {
            this.front = -1;
            this.rear = -1;
        } else {
            this.front = (this.front + 1) % this.size;
        }
        return element;
    }
}

This code defines a CircularQueue class with enqueue and dequeue methods.

How do I check if the circular queue is empty or full?

You can add two methods to check if the queue is empty or full:

isEmpty() {
    return this.front === -1;
}

isFull() {
    return (this.rear + 1) % this.size === this.front;
}

Call isEmpty() to check if the queue is empty and isFull() to check if it's full.