Sample modern prototype inheritance in Javacript

modern_inheritance.js

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call
function Product(name, price) {
  this.name = name;
  this.price = price;

  if (price < 0)
    throw RangeError('Cannot create product ' +
                      name + ' with a negative price');
  return this;
}


function Food(name, price) {
  Product.call(this, name, price);
  this.category = 'food';
}

Food.prototype = Object.create(Product.prototype);

function Toy(name, price) {
  Product.call(this, name, price);
  this.category = 'toy';
}

Toy.prototype = Object.create(Product.prototype);

var cheese = new Food('feta', 5);
var fun = new Toy('robot', 40);