Stack and queue implementations in JavaScript

stack_and_queue.js

const print = str => document.write(str + '<br>');

const ITER_COUNT = 10000;

let t0, t1;
let stack, queue;

print("====== STACK ======");

class ArrayStack {
  constructor() {
    this.arr = [];
  }

  push(val) {
    this.arr.push(val);
  }

  pop() {
    return this.arr.pop();
  }
}

stack = new ArrayStack();

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    stack.push(i);
  }
  for (let j = i; j >= 0; j--) {
    stack.pop();
  }
}
t1 = performance.now();

print(`ArrayStack finished in ${t1 - t0}ms`);

class Node {
  constructor(val) {
    this.val = val;
    this.next = 0;
  }
}

class LinkedListStack {
  constructor() {
    this.list = null;
  }

  push(val) {
    const node = new Node(val);
    node.next = this.list;
    this.list = node;
  }

  pop() {
    if (!this.list) return null;
    const val = this.list.val;
    this.list = this.list.next;
    return val;
  }
}

stack = new LinkedListStack();

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    stack.push(i);
  }
  for (let j = i; j >= 0; j--) {
    stack.pop();
  }
}
t1 = performance.now();

print(`LinkedListStack finished in ${t1 - t0}ms`);

print("");

print("====== QUEUE ======");

class ArrayQueue {
  constructor() {
    this.arr = [];
  }

  enqueue(val) {
    this.arr.push(val);
  }

  dequeue() {
    return this.arr.shift();
  }
}

queue = new ArrayQueue();

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    queue.enqueue(i);
  }
  for (let j = i; j >= 0; j--) {
    queue.dequeue();
  }
}
t1 = performance.now();

print(`ArrayQueue finished in ${t1 - t0}ms`);

class LinkedListQueue {
  constructor() {
    this.front = null;
    this.rear = null;
  }

  enqueue(val) {
    const node = new Node(val);
    if (this.rear) {
      this.rear.next = node;
    }
    this.rear = node;
    if (!this.front) {
      this.front = this.rear;
    }
  }

  dequeue() {
    if (!this.front) return null;
    const val = this.front.val;
    this.front = this.front.next;
    if (!this.front) {
      this.rear = null;
    }
    return val;
  }
}

queue = new LinkedListQueue();

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    queue.enqueue(i);
  }
  for (let j = i; j >= 0; j--) {
    queue.dequeue();
  }
}
t1 = performance.now();

print(`LinkedListQueue finished in ${t1 - t0}ms`);

class CircularQueue {
  constructor(arrSize) {
    this.arrSize = arrSize;
    this.arr = new Array(this.arrSize);
    this.size = 0;
    this.front = 0;
    this.rear = 0;
  }

  enqueue(val) {
    this.arr[this.rear] = val;
    this.rear = (this.rear + 1) % this.arrSize;
    this.size++;
  }

  dequeue() {
    if (this.front === this.rear) return null;
    const val = this.arr[this.front];
    this.front = (this.front + 1) % this.arrSize;
    this.size--;
    return val;
  }
}

queue = new CircularQueue(ITER_COUNT);

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    queue.enqueue(i);
  }
  for (let j = i; j >= 0; j--) {
    queue.dequeue();
  }
}
t1 = performance.now();

print(`CircularQueue with size ${ITER_COUNT} finished in ${t1 - t0}ms`);

queue = new CircularQueue(ITER_COUNT * 100);

t0 = performance.now();
for (let i = 0; i < ITER_COUNT; i++) {
  for (let j = i; j >= 0; j--) {
    queue.enqueue(i);
  }
  for (let j = i; j >= 0; j--) {
    queue.dequeue();
  }
}
t1 = performance.now();

print(`CircularQueue with size ${ITER_COUNT * 100} finished in ${t1 - t0}ms`);