Inherit both the properties and methods from parent.

main.js

  // Pattern to inherit both the properties and methods
  function Parent(name) {
    this.name = name || "Vladimir";
  }
  Parent.prototype.say = function () {
    return this.name;
  };

  function Child(name) {
    Parent.apply(this, arguments);
  }
  Child.prototype = new Parent();

  var kid = new Child("Wesley");
  console.log(kid.name); // Wesley
  console.log(kid.say()); // Wesley
  delete kid.name; // Note that you can only delete properties, not variables
  console.log(kid.say()); // Vladimir, gets propertie form parent