Simple Queue Implementation in JavaScript

programming web dev
3

Just for kicks, I created a version that doesn’t use shift:

class Queue {
    constructor(...items) {
        this.items = items;
        this.start = 0;
    }
    clear() {
        this.items.length = 0;
    }
    clone() {
        var newItems = this.items.slice(this.start);

        return new Queue(...newItems);
    }
    contains(item) {
        return this.items.includes(item);
    }
    peek() {
        var item = null;

        if (this.items.length > this.start) {
            item = this.items[this.start];
        }
        
        return item;
    }
    dequeue() {
        var removedItem = this.items[this.start];
        this.start++;

        return removedItem;
    }
    enqueue(item) {
        this.items.push(item);
        return item;
    }
}

Usage of this should be the same as the earlier. In my cursory testing, As I mention below, it is slower than the shift approach for some bizarre reason.

Cheers,
Kirupa