class ShoppingCart {
  constructor() {
    this.cart = [];
  }

  addItem(item) {
    this.cart.push(item);
  }

  removeItem(item) {
    this.cart.splice(this.cart.indexOf(item), 1);
  }

  listItems() {
    return this.cart.join(", ");
  }
}

const bigBasket = new ShoppingCart();

bigBasket.addItem('rice');
bigBasket.addItem('dal');
bigBasket.addItem('tomato');

bigBasket.listItems(); // rice, dal, tomato

bigBasket.removeItem('tomato');

bigBasket.listItems(); // rice, dal