ChrisGaudreau

In the context of React, it allows you to implement a `shouldComponentUpdate` method which simply compares the references of two objects, which is extremely fast. If the references remain the same, then there is no need to invoke `render` again.

Prototype-type based systems are cool in theory, but aren't much fun to use in practice. They are incredibly powerful and easy to abuse. Basically single inheritance in disguise.

Classes aren't great either, but at least using class inheritance makes you feel icky, you're not likely to have shared state on the prototype being randomly mutated, and it's pretty readable.

I think I actually had a similar problem, but using `filter`. Don't really remember though.

P:

I prefer flipped smileys. (:

Would this technique work to center, say, an <img> tag with undeclared dimensions inside of a div? Or do you have to jump through hoops?

An alternative using ES6 object parameters:

  function addObserver(observer, func, { weak = false } = {}) {
    if (weak) {
      // ...
    }
  }

  addObserver(observer, 'load', { weak: true });