inheritance2.js

inheritance2.js

function Animal() {
  this.offspring = [];
}
function Dog() {
  Animal.call(this); // Use Animal.call(this, args) if any arguments
  // exist. Else, use 'apply'
}
Dog.prototype = Object.create(Animal.prototype);
Dog.prototype.constructor = Dog;
var d1 = new Dog();
var d2 = new Dog();
var pup = new Dog();
d1.offspring.push(pup); // Dog {offspring: Array[1]}
d2.offspring; // Dog {offspring: Array[0]}