Stack

// LIFO (Last In, First Out)
export default class Stack {
  constructor() {
    this._size = 0;
    this._storage = {};
  }

  push(data) {
    const size = ++this._size;
    this._storage[size] = data;
  }

  pop() {
    const size = this._size;

    if (size) {
      const deletedData = this._storage[size];

      delete this._storage[size];
      this._size--;

      return deletedData;
    }
  }
}