Benefits of using `Object.create` for inheritance

Question

I\'ve been trying to wrap my head around the new Object.create method which was introduced in ECMAScript 5.

Usually when I want to use inheritance I do

Answer 1

First, running the Animal constructor may have undesired side effects. Consider this:

var Animal = function(name) {
    this.name = name;
    Animal.instances.push(this);
};
Animal.instances = [];

This version would keep track of all instances that have been created. You don't want your Dog.prototype to be recorded there.

Second, Dog.prototype = Animal.prototype is a bad idea, since that would mean that bark would become a method of Animal.