day12.js

// program to implement stack data structure
class Stack {
  constructor() {
    this.items = [];
  }

  // add element to the stack
  add(element) {
    return this.items.push(element);
  }

  // remove element from the stack
  remove() {
    if (this.items.length > 0) {
      return this.items.pop();
    }
  }

  // view the last element
  peek() {
    return this.items[this.items.length - 1];
  }

  // check if the stack is empty
  isEmpty() {
    return this.items.length == 0;
  }

  // the size of the stack
  size() {
    return this.items.length;
  }

  // empty the stack
  clear() {
    this.items = [];
  }
}

let stack = new Stack();
stack.add(1);
stack.add(2);
stack.add(4);
stack.add(8);
console.log(stack.items);

stack.remove();
console.log(stack.items);

console.log(stack.peek());

console.log(stack.isEmpty());

console.log(stack.size());

stack.clear();
console.log(stack.items);

// program to implement queue data structure

class Queue {
  constructor() {
    this.items = [];
  }

  // add element to the queue
  enqueue(element) {
    return this.items.push(element);
  }

  // remove element from the queue
  dequeue() {
    if (this.items.length > 0) {
      return this.items.shift();
    }
  }

  // view the last element
  peek() {
    return this.items[this.items.length - 1];
  }

  // check if the queue is empty
  isEmpty() {
    return this.items.length == 0;
  }

  // the size of the queue
  size() {
    return this.items.length;
  }

  // empty the queue
  clear() {
    this.items = [];
  }
}

let queue = new Queue();
queue.enqueue(1);
queue.enqueue(2);
queue.enqueue(4);
queue.enqueue(8);
console.log(queue.items);

queue.dequeue();
console.log(queue.items);

console.log(queue.peek());

console.log(queue.isEmpty());

console.log(queue.size());

queue.clear();
console.log(queue.items);